What is the greatest prime factor of 7!6! + 6!5! ?
Choices
A) 17	B) 23	C) 37	D) 43	E) 53
7!6! + 6!5! = 6!5!(7*6+1) = 6!*5!*43   The answer is 43.
<result>D</result>
What is the greatest prime factor of 7!6! + 6!5! ?