Number of ways of selecting 2 fiction books = 3C2
Number of ways of selecting 2 non fiction books = 6C2
3C2 * 6C2 = 3 * 15 = 45
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?
1) 90
2) 120
3) 45
4) 180
5) 200