Number of ways of selecting 2 fiction books = 7C2
Number of ways of selecting 2 non fiction books = 6C2
7C2 * 6C2 = 21 * 15 = 315
There are 7 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. 315
4. 180
5. 200