A reading list for a certain course consists of 10 books, of which 7 are poems and the rest are novels. Each student is required to read a selection of 4 books from the list, including at most 2 novels. How many selections of 4 books satisfy the requirements?  Choose the correct choice from the following options
A) 90  B) 115  C) 130  D) 144  E) 175
Ans: B   Solution: Selection requires at most 2 novels, means=   0N4P + 1N3P + 2N2P   7c1*3c3+ 7c2*3c2 + 7c3*3c1   = 7+ 63 + 105= 
<gadget id="calculator">7+ 63 + 105</gadget>
<output>175</output>
175   Ans: 175
<result>E</result>
A reading list for a certain course consists of 10 books, of which 7 are poems and the rest are novels. Each student is required to read a selection of 4 books from the list, including at most 2 novels. How many selections of 4 books satisfy the requirements?