2 ^ (2m+1) = 2 ^ (n+2)
2^2m.2=2^n.2^2
2^2m=2^n.2
2m=n+1--> equ 1
St 1 2 ^ (3n-1) = 256
2^3n/2 = 2^8
2^3n=2^9
3n = 9
n=3
Substituting in equ 1 you get m = 2---SUFF
St 2 2 ^ (m+2n) = 256
2^m.2^2n = 2^8
m+2n = 8
From equ 1 --> 2m=n+1; m=(n+1)/2
m+2n=8
(n+1)/2+2n=8
n=3, m=2---SUFF
Answer D
Thanks cramya for posting this warm up question. Hope to see more such questions. Thanks logitech for taking the initiative.
exponent ds
This topic has expert replies
Source: Beat The GMAT — Data Sufficiency |
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iamcste
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mals24 wrote:2 ^ (2m+1) = 2 ^ (n+2)
2^2m.2=2^n.2^2
2^2m=2^n.2
2m=n+1--> equ 1
St 1 2 ^ (3n-1) = 256
2^3n/2 = 2^8
2^3n=2^9
3n = 9
n=3
Substituting in equ 1 you get m = 2---SUFF
St 2 2 ^ (m+2n) = 256
2^m.2^2n = 2^8
m+2n = 8
From equ 1 --> 2m=n+1; m=(n+1)/2
m+2n=8
(n+1)/2+2n=8
n=3, m=2---SUFF
Answer D
Thanks cramya for posting this warm up question. Hope to see more such questions. Thanks logitech for taking the initiative.
Cool !
However, we are not supposed to solve in this detail..
2 variables, 2 linear equations ...sufficient....
We have to be clear in the subtle difference in DS and PS
However, if you get confidence by doing this, do it...however try to speed it up as...we cannot afford more than 2 min
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mals24
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@iamcste
Lolz i just explained it in detail so that people should not have any problem in understanding any step. Its just to make things clear. Thanks for the condensed version btw.
Lolz i just explained it in detail so that people should not have any problem in understanding any step. Its just to make things clear. Thanks for the condensed version btw.
