There are 10 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) 675
(D) 180
(E) 200 Think first, then make a decision. Some random thoughts:
Number of ways of selecting 2 fiction books = 10C2
Number of ways of selecting 2 non fiction books = 6C2
10C2 * 6C2 = 45 * 15 = 675 So the answer is (C).