 Hi and welcome to the session. I am Neha and I am going to help you with the following question. The question says Ramkali saved Rs 5 in the first week of a year and then increased her weekly savings by Rs 1.75. If in nth week, her weekly savings become Rs 20.75 find n. Let's see its solution and given in the question Ramkali savings for first week are Rs 5 then increase in weekly savings is of Rs 1.75. So the savings for first week are Rs 5. Now the savings for second week will be Rs 5 plus Rs 1.75 that is 6.75 and for third week it will be the savings for second week plus Rs 1.75 that will be Rs 8.50 and so on. Now if we see it carefully then this is a AP with the first term that is A is equal to 5 and common difference D is equal to 1.75. Now in question it is given that in nth week her weekly savings become Rs 20.75 so that means we have A n equal to 20.75 and we need to find the value of n and we also know that A n is equal to A plus n minus 1 into D where A is the first term and D is the common difference of the AP. So now substituting the values of A n, A n, D we will get here A n is 20.75 equal to A that is 5 plus n minus 1 into D that is 1.75. Now to find out the value of n we will solve this equation and for that we will subtract 5 from both the sides. So we will get 20.75 minus 5 equal to 5 plus n minus 1 into 1.75 minus 5. So this will give us 15.75 equal to n minus 1 into 1.75 as here plus 5 and minus 5 will get cancelled. Now we will divide both sides by 1.75. So this will be 15.75 upon 1.75 equal to n minus 1 into 1.75 upon 1.75 that is 9 is equal to n minus 1. That means n is equal to 10. So Ram Kali's weekly savings become rupees 20.75 in 10th week and thus n equal to 10 is the required answer to this question. With this we finished this session hope you must have enjoyed it. Goodbye, take care and have a nice day.