There are 6 fictions and 6 non-fictions. How many cases are there such that 2 fictions and 2 non-fictions are selected from them? Choices:  A) 90  B) 120  C) 225  D) 180  E) 200
Number of ways of selecting 2 fiction books = 62252   Number of ways of selecting 2 non fiction books = 62252   62252 * 62252 = 15 * 15= 
<gadget id="calculator">15 * 15</gadget>
<output>225</output>
225   Answer: 225
<result>C</result>
There are 6 fictions and 6 non-fictions. How many cases are there such that 2 fictions and 2 non-fictions are selected from them?