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kaplan #37

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kaplan #37

by magical cook » Wed Aug 22, 2007 5:22 pm
37) If 2^2m+1 = 2^n+2, what is the value of m+n?

1) 2^3n-1=256
2) 2^m+2n = 256

Hi
Can anyone help pls? correct answer will follow....
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by joey » Wed Aug 22, 2007 8:55 pm
from question we know
2m+1=n+2
hence 2m=n+1

A tells us that 3n-1=8
hence 3n=9
n=3
thus m=2
so m+n=5
A SUFF

B we know m+n=5

Ans D
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by magical cook » Thu Aug 23, 2007 7:23 am
For 2)


2^m+2n = 256

m+ 2n = 8 .... how did you get m+n=5? :?


Thank you!
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by erdnah » Thu Aug 23, 2007 7:48 am
magical cook wrote:m+ 2n = 8 .... how did you get m+n=5?
as joey said:
2m=n+1
m = 0.5n + 0.5

this yields:
0.5n + 0.5 + 2n = 8
2.5n = 7.5
n = 3

and so:
m + n + 3 = 8 (haha...)
m + n = 5 :wink:
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by magical cook » Thu Aug 23, 2007 10:29 am
Oh, Thank you! :wink:
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