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LCM & GSF DS probelm

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LCM & GSF DS probelm

by xcise_science » Fri Dec 07, 2007 12:02 pm
I've seen different variations of this question before thats how I know this is the right answer, but can someone explain to me how/why its true?

thanks

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by jayhawk2001 » Sat Dec 08, 2007 10:13 am
1 - insufficient. take d=2, d=3. 100 and 1000 are factors of 30!

2 - insufficient. again, d could be anything

30! has 7 zeroes (5*2, 10, 15*4, 20, 25*8, 30 all yield zeroes). So,
knowing that d>6 is sufficient

Is it C
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by xcise_science » Sat Dec 08, 2007 12:07 pm
oops sorry, I attached the wrong image.
here's the right one.


Image

Is it possible to delete the old one?

Thanks
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by jayhawk2001 » Sat Dec 08, 2007 4:35 pm
xcise_science wrote:oops sorry, I attached the wrong image.
here's the right one.

Is it possible to delete the old one?

Thanks
I was wondering where GCF and LCM are in the previous question :-)

Product of 2 numbers = LCM * GCF

[ For reference: https://en.wikipedia.org/wiki/Greatest_c ... ng_the_gcd ]


So, using (1) and (2), you can see that the product is a multiple of 8.

We can clearly see that either (1) or (2) by itself is not sufficient
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