gmat prep equations

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Pretty straight...

by mav800rick » Tue Jun 03, 2008 10:51 am
P+M+K=162

P=2k
P=M/3

Slving this u get P=36 / M=108 / K=18. There fore 90 hrs is the diff b/w M and K

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I got this question on my GMAT prep also

by mlane25269 » Sun Jun 15, 2008 10:33 pm
I'm still confused as to how you got from:

P=2k
P=M/3

to "90 hrs is the diff b/w M and K"

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by g_beatthegmat » Mon Jun 16, 2008 1:41 am
P = 2K ... (i)
Also, P = M/3 ...(ii)

From (i) and (ii),
2K = M/3
Or, M = 6K ...(iii)

Now, as P + K + M = 162, substitute (i) and (iii),
2K + K + 6K = 162.
=> 9K = 162
=> K = 18

Thus from (iii),
M = 6*18 = 108.

The question asks about how much M is more than K, i.e.,
M-K = 108 - 18 = 90

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by mlane25269 » Mon Jun 16, 2008 11:41 am
Ahhh I see now. That makes total sense. Thanks, g_beatthegmat! :-)