What is the greatest prime factor of (12!11!) + (12!13!)?  Choices.
A) 41	B) 71	C) 107	D) 157	E) 211
12!11! + 12!13!   = 12!11! (1+12*13)   = 12!11!(157)   The answer is 157.
<result>D</result>
What is the greatest prime factor of (12!11!) + (12!13!)?