For a positive integer x, let f(x) be the function which returns the number of distinct positive factors of x. If p is a prime number, what is the minimum possible value of f(75p^2)?

To find the minimum possible value of f(75p^2), we need to determine the prime factorization of 75p^2 first.

The prime factorization of 75 is: 3 * 5^2

Since p is a prime number, we can say that p = p^1

So, the prime factorization of 75p^2 becomes: 3 * 5^2 * p^2

To find the number of distinct positive factors, we need to consider the exponents of each prime factor. The number of factors will be the product of the incremented exponents:

(1+1) * (2+1) * (2+1) = 2 * 3 * 3 = 18

Hence, the minimum possible value of f(75p^2) is 18.