In how many different ways can 3 identical green shirts and 3 identical red shirts be distributed among 6 children such that each child receives a shirt?
A
20
B
21
C
12
D
6
Correct Answer: 20
6C3 = 6!3!3! = 6.5.4.3!3.2.1.3! = 2.5.2 = 20