Solution:
we have been asked to find
The smallest value of n such that the LCM of n and 15 is 45.
The prime factors of 15 are

So in LCM of n and 15 , we must include both the prime factors and the LCM is 45.
Since 3 is one time in the prime factor of 15. But to make 45 we need one more 3 and its possible if we take the value of n as below"
n=9

Hence the LCM will be

Hence the smallest possible value of n is 9.