Can someone please help solve this? I watched Greg’s video, but couldn’t figured it out.

There is a formula for calculating the number of distinct factors of a number. Firstly prime factorize the number. Since here n is already prime factorized, you can skip that step. So the formula goes like this: If x has only 2 and 3 as the prime factors,

x = (2^a)(3^b) then **the number of factors for x are (a+1)(b+1)**.

if x=(2^a)(3^b)(5^c) then the number of factors for x are (a+1)(b+1)(c+1)

Here in the question, n=7.19^3 so the number of factors =(1+1)(3+1)=2.4=8

There is no need to memorise. Any factor of *n* has either 0 or 1 as the power of 7, and 0 - 3 as the power of 19. There are 2 * 4 = 8 ways at most.

Thank you very much! This is very helpful.