 Okay guys, good evening. I'll be starting the session in next Two to three minutes are nearly 15 people have joined What I've observed that the attendance is nearly 25 to 30 so I'll wait for two to three minutes For people to join and then I I'll start the session. So Before people join the class What I'm going to do today is I'm going to cover up to two topics at least and the topics would be that mirror image mirror image is also called Water image that is equivalent and then I shall be taking dates and calendars and If I get time I'll cover Questions related to clocks also So these two things will be primary objective and and concepts related to clocks It depends on whether I have time at the end of the class or not So people are still joining. Let's wait for two minutes. Not more than that. It's already six five now Let's wait for two minutes So that all of them can join and then perhaps we can start after that. So I can see 1821 now So, okay, before this join, let me just go to my folder and let me just So the question is in front of you if you want to solve it you can start solving it Give me the answer up before that. Let me teach a little bit about what is mirror image and all these things So for mirror image, what I can do is what I can show you is So I just look at here and this is Accesses and suppose I have Something like this I Have a line like this first of all and then I have Circle here Something like this. Suppose I make this Two circle. Oh, let me let it be a red circle and then let me make Again a line like this, which is blue in nature and I have certain things like Something like this So I have Something like this I have On the other side. I have Something like this It's like this So now I tell you to find out mirror image. Now what I can do over here is mirror image means Equate distance from this line if this is the mirror Suppose this is the mirror all the objects image would be formed image would be equidistant From the mirror equidistant from the mirror means this line Suppose how many gaps one two gaps are there so one two gaps from here the line will start like this and This will go till once again. This will go till Yeah, so suppose it starts from here. This will go for till here The circle is after this line so circle would be after this line here also Now there somewhere in between I have this line something like this Now these two are facing the mirror. So here also these two would be facing the mirror These two are away from mirror. So these two would be away from mirror here also So this is what the mirror image of given figure would be or Water image of the given figure would be so it's something like this So you have to do the same thing over here. There is nothing much to explain So start solving the question Vanisha do it once again. Okay. One B is right answer. Just look at here If if this is something like this, I draw something like this In between I have something like this and then I have a Nonstraded and I have a shaded triangle. So I draw a mirror over here So this line, which is very near this line would be like this. This is far. So this would be far Now this line would be drawn like this But you need to understand that if this is opening away from the mirror, this will open away from the mirror now again the triangle This triangle would be on this side only but the triangle would be made something like this And this shaded triangle would also be made it something like this. So one B is your answer Okay Next Question is Next question is question number two. Just solve it Question number two solve it a lot of you have given me answer to a today is a right answer so So it's something like this you make Your mirror here so this portion smaller portion comes over here and the trapezium looks something like this so Trapezium should look something like this to see and they are gone only a and b can be my answer now if they are open they are towards the mirror here also they would be towards the mirror now if This is from here. So this would be looking like this. This is going away from the mirror So this this triangle would go away from the mirror and look at this this triangle would be It as it is this tip is away from the mirror here also the tip would be away from the mirror the box would be somewhere here and this box would be somewhere here, so Away portion would be this this portion is nearer to the mirror So this portion would be the open portion would be nearer to the mirror and the shaded portion is away from the mirror So shaded portion would be away from the mirror. So this is the answer Now let me go to third question is the third question third a is right answer because see what happens oh I'm sorry third a is right answer so I make my mirror here I'm sorry I make my mirror here so this is square will remain square now look at this so this will remain as it is now look at this this is nearer to the mirror so this particular figure would be nearer to the mirror with just one particular change that the tip is towards the mirror so tip will go towards the mirror this is away from the mirror so this will be away from the mirror some somewhere like this and this is this will remain as it is the upper portion is going away from the mirror so the upper portion here also will go away from the So which matches with A hence A is the right answer. Question number four. Question number four, a lot of you are giving me answer. And question number four, most of you have seen, a lot of you have seen D. A lot of you have said D and a lot of you are saying C. So let me check the answer. So first try to understand the answer. Answer would be something like this. So if I draw a mirror over here and to draw a square, a square would be something like this. A square would be something like this. Now after this square, try to understand. Look at this line, the line which is here. So this line would be somewhere like this. It is going away from the mirror, so it will go away from the mirror. Now you look at here, what about this particular line? So this particular line try to understand. This particular line is something like this. I don't want to draw here. It's something like this with a circle over here. Are you understanding? So what happens is if a mirror is put over here, the circle will come that side and the line will come this side. So what will happen, the circle and this line is nearer, so this line will remain nearer. So it is something like this. And now this is coming, so this will go towards the mirror, something like this. So this matches with C, so C is your answer. So the answer is C over here. Now let me move to another particular example, sorry question which is question number 5. So solve question number 5. Question number 5, few of you have given me, I mean whoever has given me answer, he has given me 5B. So 5B, let me check the answer. 5B is this will, this is opening. So 5B is what is the problem? 5B is the right answer. So there is nothing. See the graph is the triangle is away from the mirror. If I look at the triangle, the triangle is if I draw a mirror over here, if I draw a mirror over here, so triangle is away from the mirror, so triangle would be away from the mirror. All the triangles are away from the mirror. These two sides which are black, completely black, should be, so see look at here, this and this are neglected because mirror image cannot be different from the actual image, actual object. In actual object, two sides of the triangle, if four parts of triangle is there, one is white with a little circle, one is graded and the other two parts which is where I have made this particular orange sign, this is completely black. So in these two figures, these two completely black portions are not coming. So this has to be removed. This will remove because the graded portion, the lined portion is not coming. The only answer is white B. Question 6. Okay, a lot of you are saying 6A, let me check the answer. So in this trapezius, the longer side has to be towards the mirror. So longer side, in all of them, longer side is towards the mirror. Now let me look at, so this, these two circles has to be towards the mirror. Here it is not towards the mirror. So this is wrong. Now try to understand this particular portion is towards the mirror. So this particular portion has to be towards the mirror. So in this and this A and D, it is towards the mirror. So it would be something like this. Now look at this line. This line will decide this line is like this. So this line has to be like this after the mirror remains. So in both of them, so A and D till now are correct. Now this is away from the mirror. This has to be away from the mirror. So 6A is correct answer because here it is away from the mirror. Here it is going towards the mirror. So these two are or these two were rejected in the previous round. Now you can look at this and say that this is away from the mirror. This has to be away from the mirror. Indeed, it has been made towards the mirror. So that is a wrong answer. Question number 7. Let me check how many questions are there. Some good 13 questions are there. We will solve all the questions and then we will move. So it is the same thing. You remember whether it is water image or mirror image, both are the same things. Okay, 7D is the right answer. There is no doubt about it. Solve question number 8. Neglect this XY given in the question. You have to neglect this portion. Once again, I have read the question incorrectly. Sorry, don't neglect X and Y. This is mirror image. So in water image, water will not be made. In mirror image, mirror would be made. So this is XY, AB, all these things are mirror. So I just got confused between water and mirror. So look at here. So this will remain as it is. Now look at this. This is going away from the mirror. So this will go away from the mirror. This triangle will, sorry, circle will remain as it is. This is coming towards the mirror. So this will come towards the mirror, something like this. And this will be like this. So which image it is, it is B. So 8B is the answer. Now let me go to question number 9. And question number 9 is like this. 9A, it is very clear. I and H, mirror image would remain same. The two signs here, the two circles will remain same. This one circle, this circle will go down. These two circles has to go down. It is only down in A. So A is your answer. Let's go to question number. Yes, position of the, obviously position of the mirror matters. In mirror image, you have to look where mirror has been located. In water image, you always have to assume that the mirror is below this. So try to understand the difference in water image. Mirror is always below the object. In water image, mirror is, and in mirror image, mirror would be specified in the question. So depending on the position of, depending on the position of the mirror, the image has to be formed. So position of mirror matters. So I hope you understood what is the difference, basic difference of mirror image and question number 9, we have done question number 10. Okay, how options can be eliminated here, you just look at here. These two can never be my answer because here the black portion is triangle, here it is quadrilateral. So these two can never match my answer. Now look at here, this can also be eliminated because this lined segment is in the top of the triangle and mirror is here. So line segment can never be below because when you draw it, you draw it on this side. So line segment should come towards the mirror because it is towards the mirror. So this can also be rejected. So the only option left out is 9B, sorry, 10B. So answer for 10th question would be option B. Let me go to question number 11. 11A is not right answer, 11C is right answer. Here there is some gap. There is no, you try to understand here. This can never be your answer because in T, in this portion of T, there are not, I mean in the whole portion of T, the lines which have been drawn are sloped. There is some slope in the line, they are not horizontal lines so this cannot be my answer. 9 will always get formed something like this so this cannot be my answer. Now there is no difference between this and this. T looks same. The only way I can neglect A over here is there is some gap over here in 9. There is no gap here in 9. So that's why I am selecting C as the answer. Question number 12. 12 is a very easy question and 12C is the right answer. This is all about option elimination, this cannot be my answer because this is a square here, it has been made as rhombus. This can be cancelled out because here the two figures are meeting each other here. There is gap over here so this cannot be my answer. And this can be eliminated because square is here but square has to be away from the mirror, it is towards the mirror. So the only option left out is 12C. Now let's go to question number 13. 13A cannot be the answer here. Try to understand why because legs are twisted over here. Legs are not twisted so 13A cannot be my answer. 13B cannot be my answer because arms are shown twisted in the mirror image. Arms are not twisted in the original figure. 13C, look at here, make one arm. If this is like this, arms should be like this. And this arm would be somewhere like this. So arms are up over here, arms can never be down. So arms are here down so 13C cannot be my answer. So the only option is 13D. So now let me go to another particular session which is, let me check. So this is calendar type of question. So I told that I will be doing calendars for you. For calendars there are different rules. Sunmukh, I can understand, hands are short. But out of the given figures, only D was there in which hands were up. So that's why I selected. Okay, now there are different rules in calendars. So just write it down all the rules. I'll be discussing all the rules now. I'm writing here rules for calendar questions. First is yearly shift. And what do you mean by yearly shift? So the questions are like this. If first January 2007 was Monday, suppose. So what would we fast January 2008? What would be it? So this is called yearly shift. Now rules for same date in two consecutive year going forward. I mean, you are increasing the year. If leap February comes in between, then increase day by plus two. If non leap February comes in between, increase day by plus one. Now what is the reason for it? What is the reason for it? Can anyone give me reason for it? Just type it down. All of you. Why leap February you increase it by plus two? Why in non leap you increase it by plus one? I'm not asking for answer. I'm asking for reason. Why for leap February you increase it by plus two? Few of you are giving me right answer. So let me explain here. First of all, write this first rule. All of you I'm giving you 30 seconds to write this first rule. And then I'll explain why I'm saying this. I'll give explanation. So write this first rule. I'm giving you explanation. Write this first rule. Okay, the explanation is. So let me do it for non leap first. Non leap year. So in non leap year, or let me write it. N, L, Y non leap year. So that I don't have to write non leap year time and again. Non leap year is N, L, Y leap year is L, Y. So wherever I'm writing L, Y, it's leap year. In non leap year, total number of days is equal to 365. Now try to understand. In one week. Seven days are there. So what do you mean by seven days? So if first January is starting with suppose Monday here. So eighth January will also start Monday. Similarly, 15th January will also start Monday. What I'm trying to say is that each week, each new week starts with Monday. And if it is starting with Monday, it will end with Sunday. That's the thing. Now try to understand. If it ends with Sunday, then how many weeks are there? So 365 divided by 7, it gives me 52. And one is the odd number. It means that I have one odd day in a leap year. Try to understand the concept of odd day. These questions are asked very, very directly. That number of days would be given 203. And you will be asked how many odd days are there in 203 days. You just have to divide it by 7 and you get 63. So it goes 9 times. This is completely divisible. So what is the remainder here? Reminder here is zero. So zero odd days is there. So if somebody is asking you how many odd days. So you just divide the number of days by 7 and you will get the odd days. Now try to understand. Here I have one odd day. One odd day means if 52 weeks are there. So it means that 31st December would be that odd day. It means that 52nd week will end on 30th of December. And if each week is ending on Sunday, then 30th December will end on Sunday. 31st December would be Monday. And 1st January next year would be Tuesday. So if it was a non-leap year, why did it become non-leap year? Because February was of 28 days. So if a non-leap February comes in between. If a non-leap February comes in between. Then for consecutive year, thus for the same date the day will increase by plus 1. With the same logic, suppose 366 days are there. So divide it by 7, you get 2 odd days. So 2 odd days means 30th December, last 2 days, 30th December and 1st December are odd days. It means that if it is a leap year and 1st January is Monday in a leap year. Or let me take Tuesday for leap year, 1st January is Tuesday. So it means that if week is starting with Tuesday, 7th Jan would be the end of week. It would be Monday. So each week will end on Monday. So 29th December would be Monday. 30th December would be Tuesday. 31st would be Wednesday. And 1st January next year would be Thursday. So in a leap year, if it starts with Tuesday, next year it would be Thursday. Why did it happen? Because I had 2 odd days. So try to understand, whenever 2 consecutive years have been given, just try to look the February which is coming in between those 2 consecutive days. For an example, I am asking you this question. So the question is here, if 29th August 2016, before that you will ask what is a leap year. So what is a leap year? Just write that in a comment box. Let me check how many of you know leap year, non leap year, non leap year. I got only one answer. Most of you are telling me that if any year is divisible by 4, that would be a leap year. Then tell me if it is 1900 a leap year. I am asking the question is 1900 a leap year. Just let me check. Give your answer as yes or no. What do you mean by it was supposed to be? Either say yes or say no. 1900 is not a leap year. Any century year and what is a century year? Year divisible by 100 has to be divisible by 400 not 4 to be a leap year. So even though 1900 is divisible by 4 as it is not divisible by 400, it is not a leap year. So let me go to this question again. So if 29th August 2016 was Tuesday, what would be 29th August 2017? Okay, a lot of you are saying Wednesday. It is Wednesday. It will not be Thursday. Try to understand what I am trying to the concept I am trying to inculcate is look at the February coming between two consecutive years. So 29th August 2016 Feb 2016 is a leap year. But Feb 2016 is already passed. So in between these two Feb 2017 will come. Now this Feb 2017 is not leap. And if it is not leap, then I'll increase the day. Then increase the day by plus one. That's it. Answer would be Wednesday. Now another rule. I am asking you that 18th May 2019 is Saturday. What would be 18th May 2050? Now let's say 48. How do you solve this question? Those who are giving me answers. How many of you? Shreyas has given me answer. Dev has given me answer. Can you please tell me what's your... This is not 2020 or something. Dev just give me explanation how it is Monday. Those who are giving me answer, Sunday, Monday explain and then give answer. So first write explanation and then write your answer. What do you mean by two days added in leap year? If 2019 is Saturday, leap year means 2020 or 2020. If you could have given, I could have understood the answer. Look at here, the rule is... Try to understand. The rule is, leap year repeats itself after every 28 years. Now you can ask me, what do I mean by repetition first of all? You can say that leap year comes after every 4 years. So why am I saying that leap year repeats itself after 28 years? So repetition means in a calendar for same day or for same date, same day should come. So try to understand. If 18th May 2019 is Saturday, then I will go to nearest. I shall go to nearest leap year. Nearest leap year to 2019 would be 2020. So 2020 18th May would be plus 2 because the leap February which will come would be of February 2020, leap February. So that will become Monday. Now if 2020 is Monday, 2020 plus 28 is 2048. It means that leap year 2020 will repeat itself in 2048. So that would be what? That would also be Monday. So answer over here is Monday. So remember always leap year repeats itself after 28 years. So if longer period has been given to you, okay solve a question. If 18th May 2019 is Saturday, then what would have been 18th May 1963? Solve this question. I am also checking. Somebody told me that on Google it is giving Tuesday. I am also checking on Google only. 18th May 2048 is Monday. So check if you are googling it for the answer, at least Google it properly. We are googling it for answer that if this kind of question you want to Google it, Google it and give me the answer. But if you Google it, Google it properly. It's Monday only. So what I do is it doesn't matter you are verifying or not. The question is whether you checked it correctly or not and don't verify it with me. If you have to Google it and Google gives the right answer then Google it and find it out. I didn't ask 2048, I didn't ask 2047. And 2047 would not be Tuesday for that sake. 2047 would be Saturday itself because 2048 is a leap year. So it will be a two day backward direction. So Monday minus two is Saturday. It will not be Tuesday. 18th May 2019 is Saturday. Then 18th May 2020 would be Monday. We just found it out. Now I have to go backwards. So I will subtract 28 from here. I will get 1992. But I am not reaching 63. So I will again subtract 28 from here. So if I subtract 28 from here, I get 1964. So 18th May 1964 would be Monday. I have to go for 1963. Now try to understand. 18th May 1963 and 1962. Feb 1964 will come. It is a leap February. From 1963 it will be X plus 2. So if it is X day in 1963, X plus 2 would be Monday. So what should be X? X should be Monday minus 2. Monday minus 2 means what? Monday minus 2 means Sunday, Saturday. So X comes out to be how much? Saturday. So answer is what? Saturday. Next concept. Monthly shifting. Monthly shifting is what? There is only one rule. Calculate odd days. So months are of four types. One which has 31 days. So 31 divided by 7. 3 odd days. Why divide 31 by 7? So you get it goes 4 times. And it gives 3 odd days. So 30 divided by 7 is equal to 2 odd days. Then see 29 days. So 29 divided by 7 is equal to 1 odd day. And for 28 days, 28 divided by 7 it means that 0 odd day. So what does it mean? It means that try to understand I am taking one example. 15th January to 15th February. And then if February is non-leap. And then if February is leap. So let me do it for you. Suppose 15th January is Monday. What would be 15th February? So look at here. Just look at the month. Which you are crossing. It means that January to February. Which month's last day is coming. So from 15th January to 15th February. January's month last day is coming. Which is 31st January. So it means that if in January I have 31 days. The number of odd days would be 3. So I will add plus 3 here. So Monday plus 3 is Monday plus 1 is Tuesday. Tuesday plus 1 is Wednesday. And Wednesday plus 1 is Thursday. So Monday plus 3 is Tuesday Wednesday Thursday. So this 15th February would be Thursday. Now if it is a non-leap February it means that I have 28 days. So 15th March would be as in 28 days 0 odd days come. So if it is 0 odd days. It means that no number of days would be added. So Thursday will remain Thursday. If it is a leap year. Then try to understand. In leap year it would be of 29 days. So odd days would be 1. So 15th March in a leap year will become Thursday plus 1 Friday. Now let's go to from March. Suppose I take non-leap only. So for non-leap year. 15th March. Here 15th March is Thursday. So 15th April would be how much? Which month I am crossing? I am crossing March. If I am crossing March. Or let me say last day of March is coming. If last day of March is coming I will check. How many days in March? 31 days in March. So 3 odd days. Thursday plus 1 is Friday. Then plus 1 is Saturday plus 1 is Sunday. So 15th is Sunday. Then what about 15th May? Can you tell me what would be 15th May? What about 15th May? 15th May would be last day of April is coming. So plus 2 odd days. Tuesday. What about 15th? This is me. What about 15th June? 15th June is plus 3 so Friday. Then 15th July is plus 2 so Sunday. Then 15th August is plus 3 so Wednesday. 15th September is plus 3. August is of 31 days. So plus 3 is Saturday. 15th October is again Monday. And look at here. In January 31 days are there. And in October also 31 days are there. And first 15th look at here. If you remember 15th January was Monday. 15th October is coming out to be Monday. So next rule is calendar of January is equal to calendar of October in non-leap year. And similarly we will find out calendar of January is equal to calendar of July in leap year. Just write these two rules. Very important rules. And then solve a question. 15th August. Which day was there on 15th August? 15th August 1947 was Friday. Then what would be 26th January? What would have been 26th January? 1950. What's the answer? Not got any answer for this question. Few of you are saying Monday, Thursday, Thursday, Thursday. Wednesday, Thursday. Varied answer. Monday. Okay. Let me solve it. 15th August 1947 is Friday. So 15th August 1948. So in between 548 will come. Look at the method by which I am solving. I am always writing the February coming in between. 548 is leap. So it will be plus 2. So this becomes Sunday. Then 1949 I know don't need to write. This will be a non-leap February here plus 1. It would be Monday. Now what I have to do? 15th August 1949. Now try to understand. I have to move forward monthly. So September would be how much? I am crossing August plus 3 here. So this will be Wednesday. So for October it will be 15th September. 15th October I am crossing September plus 2. So what it will be? Friday. For November it will be plus 3. So Monday. For December it will be plus 2. So what it will be? Wednesday. Then December to January 15th December to 15th January plus 3. So Wednesday plus 3 is how much? Wednesday plus 3 is Saturday. Now 15th January is Saturday. So 22nd Jan would be Saturday. So have I missed somewhere something? August 2 September plus 3. So Monday plus 3 is Wednesday. September to October is plus 2. So Friday. October to November is plus 3. So Monday. Friday, Saturday, Sunday, Monday. November to December is plus 2. So Monday plus 3 Wednesday. And December to January is plus 3. So Wednesday, Thursday, Friday is Saturday. If this is Saturday then what happens? 15th. 29th Saturday. So how much it comes? It comes out to be. I am missing somewhere something. I remember this answer. 22nd would be Saturday. 23rd would be then Sunday. So 26th January comes out to be Wednesday in my case. Where have I missed? So 1948 is Sunday. 49 is Monday. August, let me correct it once again. Somebody is saying 15th. Oh Monday plus 3 is not Wednesday. Now Monday plus 3 is Thursday. So here only I have done mistake. So this is Thursday. So this is Saturday. So this is Tuesday. So this is not Wednesday. This is Thursday. So this is Sunday. Increase it by plus 1. Instead of Thursday I wrote Wednesday. So this is Sunday. So this comes out to be Thursday. This is the right answer. So it will be plus 2. Okay, write down one more question. If 2018th May. 2019 is Saturday. Then 18th May. So try to understand. 1879 would be what? Okay. I don't know how many of you are getting it right. But Sunday, Saturday, Sunday, Saturday, Sunday. I'll wait for more answers. Okay. A lot of people are not answering me now. So let me go back. Let me write this. 18th May 2020 would be Monday. So let me just check the difference between 2019. I don't know how many of you did it. But I chose 1879. This is 9 minus 9 0. 11 minus 7 is 4. And 9 minus 8 is 1. So this is 180 years. This is exactly 28 into 5. So it means that in 1880, which is exactly 140 years, multiple of 28, 18th May would be, should be Monday. But would it be Monday? I don't know. You can tell me. If it is not Monday, then it is what? Tell me. Try to understand. It will not be Monday. It will be Tuesday. Why I am saying it will be Tuesday? Because try to understand. You may say that, sir, this is 1880, which is 140 years away from now. You told that in every 28 years, the leap year will repeat itself. So 140 years in 140 years, there are 5 leap years. 5 times it should get repeated. But instead of Monday, you are writing Tuesday. Why I am writing Tuesday? Because try to understand in between this period 1900, which was supposed to be a leap year is not a leap year. So that is why just before 1900, all the days where it is Monday, I'll add plus 1. Because I am going backward, I had to subtract minus 1 from the day. I will not subtract minus 1 created due to 1900. Because this is not a leap year. So 18th May, 1880 would be Tuesday and 1879. Because frame 1880 will come in between, which is a leap year. So I will do minus 2 from here. So that would be Sunday. Why I am not taking it Monday? I am taking it Tuesday. Because try to understand I cannot take it Monday. Because if I am taking it as Monday, I am assuming that 1900 is a leap year. But 1900 is not a leap year. That is why there would be one less subtraction. Because 29th February, 1990 does not exist. This day does not exist. It removes minus 1. One subtraction if I am going backward. So it removes that minus 1. So instead of Monday, it will be Monday plus 1 Tuesday. And that is why 1879 would be Sunday. So I hope you understood these things. Okay, let me now go to solve this. How many questions are there? Let me just check. Good 20-25 questions are there. There are questions based on clock also. So 2008 to 2009, it is Tuesday. Tuesday plus 2 is Thursday. So first answer is Thursday. Second answer is 8th January, 2000. 8th December 2007 to 8th December 2006. So February which would be coming is February 2007 which is a non-leaf February. So that is why it would be Saturday minus 1 Friday. So second answer is D. Third answer, 6th March 2005 falls on. So 6th March, it is minus 1 because 28th February 2004 has not come. So that is why it would be minus 1. So Monday minus 1 is Sunday. So third answer is A. Now I will go to question number 4. Question number 3 is definitely A. There is no doubt about it. Question number 4, the calendar of the year 2007 will be same for the year. So try to understand in this kind of question, I do like this. First Jan 2007, I will assume as Monday. So now 2008 would be Tuesday. 2009 would be Tuesday plus 2 because February 2008 is coming. So first day. 2010 would be what? Friday. 11 would be Saturday. 12 would be this is Saturday. 12 would be Sunday. 13 would be again Tuesday. 14 would be try to understand. It will be 11 years. It is 4n minus 1 kind of number. So I think the answer should be 2018. So 14 would be Wednesday. 15 would be Thursday. 16 would be Friday. 17 would be Friday plus 2 Sunday. And 18 would be Monday. So try to understand there are 4 kinds of years. So 1 is leap year. Leap year will repeat. Leap year is 4n kind of number. Number which is divisible by 4. Will repeat itself after 28 years. 1 year before the leap year. 4n minus 4n plus 3 kind of number. Will repeat itself after 11 year. Let's do it for here only for 2 other type of numbers. So I am taking 2005 and 2006. So 2005. Fast Jan 2005. This is 4n plus 1 kind of number. 1 year ahead of 1 year after leap year. If this is Monday. 6 would be Tuesday. 7 would be Wednesday. 8 would be Thursday. And 9 would be Thursday plus 2 Saturday. 10 would be Sunday. And 11 would be Monday. So how many years? 6 years. It repeated itself after 6 years. So Monday, Tuesday, Wednesday, Thursday. No one thing I have left. In between I have left Friday. Try to understand. No sorry. Saturday. 10 it will be Sunday. And 11 Friday. So 6 years. I forgot this to tell you. 6 years. Then 2006 I will tell. So if it is Monday first Jan. So 7 it will be Tuesday. 8 it will be Wednesday. 9 it will be Wednesday plus 2 Friday. 10 it will be Saturday. 11 it will be Sunday. And 12 it will be Monday. So again it is 6 years. So try to understand there are 3 kinds. Foreign will repeat itself after 28. Foreign plus 1 6 years. Foreign plus 2 6 years. And foreign plus 3 11 years. Remember these rules. Just write it down. 2012 is a leap year but I am not reaching February. I am only reaching till 1st January. So February of 2012 is not coming. That is why it will be Monday only not Tuesday. So question number 4. If you knew these formulas you could have done directly. Now solve this. Question number 5 and 6. How I solve this question is like this. 28th Feb 2008 is Wednesday. So 28th Jan 2008 would be Wednesday minus 3 because in between and you are crossing last day of January is coming 3 odd days so it will be Sunday. So 28th July 2008 because in leap year Jan and July are equal. July 2008 it would be Sunday. So now let's go to August. August would be plus 3 Wednesday. September would be plus 3. Wednesday plus 3 Friday. October would be Wednesday plus 3 Saturday. I am sorry. This is plus 3 so Saturday. This will be plus 2 so Monday. Now October 20th October is Monday. So 20th November would be what? Monday plus 3 Thursday. Now 20th November is Thursday. So 13th November is Thursday. Now go backward. 12th would be Wednesday. 11th would be Tuesday. 10th would be Monday. So answer is Monday B. Question number 6. 3 day earlier than Tuesday means Saturday. So 5th was Saturday. So 12th again would be Saturday. So 12th is Saturday so 15th would be Tuesday. So what I have to write? Write the number of day counting. So it would be Tuesday is 2. Answer is 2. What is the answer? Question number 6B. Question number 7C. Question number 8. Question number 7. 8th November 2002 was Tuesday. 28th October 2003. So let's go to 8th November only. So 8th November 2002 now. 2003 none of them are repeated. So 8th November 2003 would be Tuesday plus 1 Wednesday. So 8th October would be last day of October is coming. So minus 3 is Sunday. 8th October is Sunday. So 15th and 22nd October is also Sunday. What I have been asked 20th October. So minus 2 day answer would be Friday. So 7C. Question number 8. Concept of clocks I will do it in the next week. So if we are done with the question of calendars we will wrap up the session. And then we will meet next week to discuss the concept of clocks and all other concepts. Okay. 1980 we all understand that. It's a leap year. So 3rd March minus 1 is 2nd. Minus 2 is 1st. Minus 3 is 29th February. Minus 4 is 28th February. So 28th February 1980. Was a wise birthday. Now Republic Day of that year fell on Saturday. So 26th Jan 1980 was Saturday. So 26th Feb would be Saturday plus 3. Sunday Monday Tuesday. So 28th would be Thursday. Why are you writing 5? How did you get 5? If Monday is 1. Are you getting Friday? 3rd March is 1980. X birthday. Birthday of Y is 4 days. Y was born 4 days. So 28 plus 1 is 29. Plus 1 is 30. Sorry. Plus 1 is 1st. Then 1st plus 1 is 2nd. And 2nd plus 1 is 3rd. So he was born on 28th February. Now if 26th Jan Republic Day is Saturday. 26th February would be Saturday plus 3. Saturday plus 3 is... No it's not 29th February. It's 28th February. 3rd March minus 4 is 28th February. So if you are taking 29th February as a birthday of Y you are wrong. 3rd March minus 4 days would be... 3rd March minus 1 would be 2nd March. 3rd March minus 2 would be 1st March. 3rd March minus 3 would be 29th February. 3rd March minus 4 would be 28th February. So birthday is 28th February. Birthday is 28th February. And if 26th January is Saturday. 26th February would be Saturday plus 3. So Sunday, Monday, Tuesday. So 28th February would be Tuesday plus 2. Thursday. So that is 4. So answer is A. So one person will write 8C. All other will copy 8C. That's how I say why all the answers are... All of them are getting correct answer. So all question number 9 that is the last question. Question number 9. 14th August 1989 was Friday. So what would be 6th July 1988? First of all try to understand if we go back from 14th August 1989 to 14th August or even 14th July 1988. Feb 1989 will come which is non-leapier. So I have to subtract minus 1 only. So 14th August 1988 would be Friday minus 1. First day. Then 14th July would be... So I am going from August to July. July last is 31st so 3. Thursday minus 3 is Monday. So I have 14th July is Monday. 7th July would be Monday. 6th July would be Sunday. So answer is Sunday. Most of you are getting it wrong. I will once again do it. 14th August 1989. What is it? Friday. Then 14th August 1988. What is it? In between what is coming? Feb 1989 is coming which is non-leapier February which is minus 1. Friday minus 1 is what? First day. Now 14th July let me find out. 1988 it would be minus 3. So Thursday minus 3 is Monday. So 7th July would be... 7th July would be Monday. Every day is repeated after 7 day. So whatever is on 14th the same would be on 7th. So 6th July would be Sunday. Answer is Sunday not Monday. So this is it for today. See you next week with questions of the concept of clocks and some other topics. So till that time keep on solving QOD questions. And I will meet you next week. Thank you so much. Thanks for the class.