Number of ways of selecting 2 fiction books = 3C2
Number of ways of selecting 2 non fiction books = 6C2
3C2 * 6C2 = 3 * 15 = 45
This justifies what answer for what question? Q & A:
There are 3 fictions and 6 non-fictions. How many cases are there such that 2 fictions and 2 non-fictions are selected from them?
Options:
(A) 90
(B) 120
(C) 45
(D) 180
(E) 200
(C)