pls help

We first determine the largest positive integer value of n such that 3^n | 15!. We determine this by counting the number of factors of 3 in the product. There are 5 multiples of 3 in the product, and there is one extra factor of 3 in 9, so there are a total of 5 + 1 = 6 factors of 3 in the product of the first 15 integers. So, for all n between 1 and 6, inclusive, 3^n is a factor of 15!
so it is 6

15!   =

1 * 2  * 3  *  4  * 5 * (2*3)  * 7 * 8 * (3 *3) * 10 * 11 * (4*3) * 13 * 14 * (5*3)   =

3 * 3 * 3 * 3 * 3 * 3  *  (all the rest)

 n  =  6 positive integer values