Is how many ways can you choose 4 Cd's from a stack of 8Cd's a combination or permutation?

Answer 1

Any 4 from 8 is a permutation, solved by the use of factorials:

8!/((8-4)! x 4!) which simplifies to (8 x 7 x 6 x 5)/(4 x 3 x 2) ie 70 different ways.