trailing zeros

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trailing zeros

by sanju09 » Tue Feb 24, 2009 5:58 am
How many trailing zeros will be there after the rightmost non-zero digit in the value of 25!?

A. 25
B. 8
C. 6
D. 5
E. 2
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by bluementor » Tue Feb 24, 2009 6:05 am
-BM-

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by bluementor » Tue Feb 24, 2009 6:11 am
120 = 1x2x3x4x5x6x..... x24x25

A new zero is introduced at these multiplications:

4x5
9x10
14x15
19x20

2 zeros are introduced for this multiplication:
24x25

Therefore, 25! has 6 trailing zeros. Choose C.

-BM-