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by selango » Tue Aug 03, 2010 4:16 am
For 3^k to be a factor of p,we need to know how many 3's are there in p.

From 3 to..30 there are ten 3's.[Check the right side of multiple]

1*3=3

2*3=6

3*3=9

10*3=30

Extra four 3's are in 3,6,9[Check the left side of multiple]

total=14

-->3^14

Pick C
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by pradeepkaushal9518 » Tue Aug 03, 2010 4:39 am
what is extra four 3's i dont understand
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by selango » Tue Aug 03, 2010 4:50 am
There ll be more than one 3 in 9,18,27.In remaining multiple of 3,there ll be only one 3.
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by selango » Tue Aug 03, 2010 6:09 am
Pradeep,

Just now remembered the formula.

You need to find number of 3's in 30!

30/3+30/9+30/27

=10+3+1[Take the quotient]=14

So 3^14..
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