GMAT Problem Solving (PS) | Re: What is the greatest value of x such that 10^x is a factor of 20! ?

10 = 2*5

The highest value of 2 in 20! will be - 18

20/2 = 10
10/2 = 5
5/2 = 2
2/2 = 1

The highest value of 5 in 20! will be - 4

20/5 = 4

Since, there are fewer 5's than 2 , the greatest value of x such that 10^x is a factor of 20! will be x = 4

Hence, correct answer will be (D) 4
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