beginners'bin#5

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beginners'bin#5

by sanju09 » Sat Mar 27, 2010 4:03 am
What is the greatest value of a positive integer n such that 3^n is a factor of 18^15?
(A) 15
(B) 18
(C) 30
(D) 33
(E) 45


no OA for now
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by eaakbari » Sat Mar 27, 2010 4:04 am
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by pops » Sat Mar 27, 2010 7:57 pm
sanju09 wrote:What is the greatest value of a positive integer n such that 3^n is a factor of 18^15?
(A) 15
(B) 18
(C) 30
(D) 33
(E) 45


no OA for now
18^15 = ((3^2)*2)^15 = (3^30)*(2^15)

hence n=30