 Hello and welcome to the session. In this session we discussed the funny question that says, on the first term of the HP whose second term is 3 upon 4 and the third term is 3 upon 7. Before we move on to the solution, let's see when a sequence say ABC and so on is a harmonic progression that is HP to sequence with terms ABC and so on is a harmonic progression when the lesson pokers of these terms that is 1 upon A, 1 upon B, 1 upon C and so on key idea that we use for this question. Let's move on to the solution equation. We are supposed to find out the first term of the HP whose second and the third term are given. So first of all, we suppose let HP, HP is 4, 3 upon 7 means we have that A upon 7 harmonic progression that is HP. From the key idea we know that the sequence ABC and so on is a harmonic progression when the lesson pokers of these terms that is 1 upon A, 1 upon B, 1 upon C and so on form an arithmetic progression. Now since these three terms are in HP, this means that the lesson pokers of these terms that is 1 upon A, 4 upon 3 and 7 upon 3 are in arithmetic progression that is AP. Now as these three terms are in AP, so this means that 4 upon 3 that is the second term minus the first term which is 1 upon A is equal to the third term that is 7 upon 3 minus the second term which is 4 upon 3. So here we get the LCM as 3A minus 3 is equal to 4 upon 3 that is 4A minus 3 upon 3A is equal to 3 upon 3 and so on with these three and here we get 1. So we now have minus 3 is equal to 3A is equal to 3 that is A is equal to 3. And we have assumed A to be the first term of the HP, HP that is the harmonic progression is the second term of the HP understudy solution of this question.