What is the greatest positive integer x such that 7^x is a factor of 343^10?  Choose one: A) 5 B) 9 C) 10 D) 20 E) 30
343^10 = (7^3)^10 = 7^30   ANSW30R:30
<result>E</result>
What is the greatest positive integer x such that 7^x is a factor of 343^10?