3^k

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3^k

by gmat740 » Tue Jul 21, 2009 4:53 pm
If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for
which 3^k is a factor of p?

A. 10
B. 12
C. 14
D. 16
E. 18

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by shibal » Tue Jul 21, 2009 4:58 pm
IMO C
OA?

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by gmat740 » Tue Jul 21, 2009 7:04 pm
yes OA is C

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by scoobydooby » Tue Jul 21, 2009 7:29 pm
30/3+30/(3^2)+30/(3^3) (stop at 3^3 as 3^4 >30)

=> 10+3+1 (taking the sum of the integral quotients)
=14

hence, C

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by ykk » Wed Jul 22, 2009 3:12 am
scoobydooby wrote:30/3+30/(3^2)+30/(3^3) (stop at 3^3 as 3^4 >30)

=> 10+3+1 (taking the sum of the integral quotients)
=14

hence, C
scoobydooby, could you please explain your logic hear? Thanks.

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by scoobydooby » Wed Jul 22, 2009 9:42 am
ykk,
refer to Ian's post in the link for the detailed explanation

https://www.beatthegmat.com/ps-confused- ... 21955.html