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diehard_gmat
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Note that factorial of any integer greater than 1 is even.diehard_gmat wrote:What is the highest power of 2 in (1! + 2! + 3! + 4!.....100!)?
A. 0
B. 2
C. 10
D. 50
E. 100
Hence, the sum (2! + 3! + 4! + ... + 100!) is even too.
Now when we add 1! = 1 to this sum, we will have an odd number. Hence, the given expression is odd, i.e. not divisible by 2.
Therefore, highest power of 2 in the expression is zero.
The correct answer is A.
