 Hello and welcome to the session. In this session we discussed the following question which says find the least square number which is exactly divisible by each of the numbers 6, 9, 15 and 10. Let's proceed with the solution. Now the least number divisible by each one of the numbers 6, 9, 15, 10 is their LCM. So first we find the LCM of the given number 6, 9, 15 and 10. Now 2, 3 times is 6, 5 times is 10, then 3, 1 times is 3, 3, 3 times is 9, 3, 5 times is 15, then 3, 1 times is 3, then 5, 1 times is 5. So from here we get LCM of the numbers 6, 9, 15, 10 is equal to 2 into 3 into 3 into 5 which is equal to 90. Thus we say the least number divisible by the number 6, 9, 15, 10 is 90. Now we do the prime factorization of 90. We know that 2, 45 times is 90, then 3, 15 times is 45, 3, 5 times is 50 and 5, 1 times is 5. Thus we say by prime factorization we get 90 is equal to 2 into 3 into 3 into 5. Now in this prime factorization of the number 90, we make pairs of the same prime numbers. Now here as you can see we get just one pair of the prime number 3. Now since the other prime numbers 2 and 5 do not make pair with the same primes. So the number 90 is not a perfect square. To make 90 a perfect square it must be multiplied by 2 into 5. That is now 90 multiplied by 10 gives us 900. Thus we say hence the required number is 900. So final answer is the least square number which is exactly divisible by each of the numbers 6, 9, 15 and 10 is 900. So this completes the session. Hope you have understood the solution for this question.