Tell wether the situation is a permutation or combination. Then solve.
1. How many ways can you choose 4 CDs from a pack of 8 CDs?
2. How many ways can 3 pairs of shoes be chosen from 8 pairs?
3. How many ways can 9 runners be arranged on a 4-person relay team?

Question

Tell wether the situation is a permutation or combination. Then solve. 
1. How many ways can you choose 4 CDs from a pack of 8 CDs?
2. How many ways can 3 pairs of shoes be chosen from 8 pairs?
3. How many ways can 9 runners be arranged on a 4-person relay team?

directrix · Answer

1. Combination - order is not a concern
C(8,4) = 70
2. Assuming that the shoes are matched in pairs, a combination.
C(8,3) = 56
3. Permutation - order matters
9*8*7*6 = 3024