Question

If AB is a two digit number in base n such that (AB)n = 5(BA)n, which of the following is a possible value of n?

Answer 1

what are the options ... it's easier to guess and check

Answer 2

what are the options?

Answer 3

If n < 10, then n =5.
If n can be bigger than 10, you can have other values of n
Here is a possible {A,B,n} in the list below:

{{1, 0, 5}, {2, 0, 5}, {3, 0, 5}, {4, 0, 5}, {5, 0, 5}, {6, 0, 5},
{6,1, 29}, {7, 0, 5}, {7, 1, 17}, {8, 0, 5}, {8, 1, 13}, {9, 0, 5}, {9, 1, 11}}