From 5 positive numbers and 6 negative numbers, how many groups of 4 numbers, yielding a positive product, can be formed? Choices
A) 170	B) 625	C) 30	D) 960	E) 255
The number of ways to choose 4 positive numbers is 5C4 = 5.   The number of ways to choose 4 negative numbers is 6C4 = 15.   The number of ways to choose 2 positive and 2 negative numbers is 5C2*6C2 = 10*15= 
<gadget id="calculator">10*15</gadget>
<output>150</output>
150.   The total number of groups is 5+15+150= 
<gadget id="calculator">5+15+150</gadget>
<output>170</output>
170.   The answer is 170.
<result>A</result>
From 5 positive numbers and 6 negative numbers, how many groups of 4 numbers, yielding a positive product, can be formed?