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?  Choose the correct choice from the following:
A) 90	B) 120	C) 315	D) 180	E) 200
Number of ways of selecting 2 fiction books = 73152   Number of ways of selecting 2 non fiction books = 63152   73152 * 63152 = 21 * 15= 
<gadget id="calculator">21 * 15</gadget>
<output>315</output>
315   Answer: 315
<result>C</result>
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?