 Hello and welcome to the session. In this session we discussed the calling question which says, a teacher on attempting to arrange the students for mass drill in the form of a solid square found that 25 students were left. When he increased the size of the square by 2 students he found that he was short of 23 students. Find the number of students. So in this question we need to find the total number of students in the mass drill according to the conditions given in the question. So let's move on to its solution. As given in the question, the teacher arranges the students for the mass drill in the form of a solid square. So for this we first assume let the total number of rows in the square formed be equal to x and we also assume let the number of students in each row of the square formed be also equal to x. So the total number of students the square formed is equal to the total number of rows which is x multiplied by the number of students in each row which is also x. So this is equal to x square. Now let's find out the total number of students in the drill and this would be equal to the total number of students in the square formed that is x square. As in the question is given that when the students are arranged in the square then 25 students were left. As the 25 students were not arranged in the square only x square students were arranged in the square. So total number of students in the drill would be equal to x square plus the number of students which were left which is 25. Now next condition given in the question is that when the size of the square is increased by 2 students then the teacher was short of 23 students. So when the size of the square is increased by 2 students then the number of students in the square would be equal to x plus 2 whole square. Now according to the question we have that when the size of the square is increased by 2 students then the teacher was short of 23 students. Which means that the total number of students in the drill which is x square plus 25 this would be equal to x plus 2 the whole square minus 23. Let's solve this now. So this would give us x square plus 25 is equal to x square plus 4x plus 4 minus 23. Now x square x square cancels so we have 4x is equal to 25 plus 23 minus 4. This further gives us 4x is equal to 48 minus 4 that is we have 4x is equal to 44. From here we get x is equal to 44 upon 4. Now 11 4 times is 44 so we get x is equal to 11. We had assumed the total number of rows in the square formed is x and the number of students in each row in the square formed is also x. And the total number of students in the drill were x square plus 25. So as we have got the value for x so this means total number of students in the drill is equal to 11 square plus 25 that is equal to 121 plus 25 which comes out to be equal to 146. So our final answer is number of students is equal to 146. So this completes the session. Hope you have understood the solution of this question.