Question

Using no digits other than 5 and 8, make a 6-digit number, that has the properties below. If it is impossible, write so. Of course you may use each digit more than once. c A multiple of 5, but not a multiple of 15.

Answer 1

Doing this would be impossible

Explanation:

Doing this would be impossible. This is because the final digit and the first digit in the 6-digit number would always be a 5 or an 8. This means that the entire 6-digit number will either be completely divisible by both 5 and 15 or neither. Therefore not meeting the requirements that have been set. So in conclusion, this would be impossible to do by using only 5's and 8's as the single digits.