P & C

Number of zeroes at the end of the number rr where r varies from 1 to 25, is

(a) 50 (b) 49 (c) 49 (d) 100

1 Answers

865
Soumyadeep Basu ·

The number of zeroes at the end=the exponent of 10 in the product=the exponent of (2X5) in the product. As the 2's outnumber the 5's, it will be sufficient to just count the number of 5's=(5+10+15+20+2X25)=100. (d).

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