Counting numbers are to be formed using only the digits 9, 3, 5, 8, 7, 6, 4, and 1. Determine the number of different possibilities for two-digit numbers.

64.

Step-by-step explanation:

There are 8 digits in the list.

This will be the number of permutations of 2 from 8 plus the duplicate numbers 11, 22 etc.

So we have 8P2 + 8 possibilities.

= 8! / (8-2) ! + 8

= 56 + 8

= 64.