Study and Strategy questions relating to the GMAT.
kittupriya.rv
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Pls help me in solving this question

by kittupriya.rv Sat Nov 05, 2011 12:15 am

find the number of consecutive zeros at the end of 100!+200!. the given answer is 24 how is it possible?? 100! contains 24 zeros and 200! contains 49 zeros then hw cum the answer will be 24 pls explain in detail thanks in advance..
atulgoel4u
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Re: Pls help me in solving this question

by atulgoel4u Sun Nov 06, 2011 11:47 am

100! + 200! = 100! (1 + 200.199.198. .....101)

1 + 200.199.198 ....101 will have a 1 at the end

Now number of zeroes at the end of 100! is [100/5] + [100/25] = 20 + 4 = 24

Hence multiplication of 100! (1 + 200.199.198 ....101) will have 24 zeroes after 1.
StaceyKoprince
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Re: Pls help me in solving this question

by StaceyKoprince Mon Nov 07, 2011 2:32 pm

Please read (and follow!) the forum guidelines before posting.

This folder is only for general strategy questions, not content or specific test problems. Check out the problem folders and post in the relevant folder depending upon the source of the problem you want to post (and make sure to follow the rules about banned sources). If you are a course student, you can also ask about other problems or issues before or after class or during office hours.

I'm locking this thread; if you want to discuss this further or discuss with an instructor, please re-post according to the guidelines.
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