What is the greatest prime factor of (11!10!) + (11!12!)? Choose the correct choice from the following choices:  A) 11  B) 17  C) 19  D) 23  E) 29
11!10! + 11!12!   = 11!10! (1+11*12)   = 12!11!(133)   = 12!11!(7*19)   The greatest prime factor is 19.   The answer is 19.
<result>C</result>
What is the greatest prime factor of (11!10!) + (11!12!)?