Question

Permutations.... How many different positive integers of 2 digits each can be made with the digits 2, 4, 5, and 8, if no digit is repeated in a number?

Answer 1

Think of it this way:
_ _ (2 digit number)
for the first blank you could have 4 possibilities
for the second blank you could have 3 possibilities
4×3=12
there are 12 possibilities