What is the greatest value of positive integer x such that 2^x is a factor of 100^50?	Choose the most appropriate option
A) 70 B) 80 C) 90 D) 100 E) 120

Rationale: put in simple words , we need to find the highest power of 2 in 100 ^ 50 100 = 2 ^ 2 * 5 ^ 2 therefore 100 ^ 50 = ( 2 ^ 2 * 5 ^ 2 ) ^ 50 = 2 ^ 100 * 5 ^ 100 answer : d
Answer: D