Operation Problem

[monteleone82]

Please help with this question from GMAT Prep.


If the operation @ is defined for all positive integers x and w by x @ w = 2^x/2^w, then (3 @ 1) @ 3 =

A. 2
B. 4
C. 8
D. 16
E. 32

[kmittal82]

2^x/2^y = 2^(x-y)

You need to work the value in the () first:

(3@1) = 2^(3-1) = 2^2 = 4
4 @ 3 = 2^(4-3) = 2
Answer is A

[amising6]

Please help with this question from GMAT Prep.


If the operation @ is defined for all positive integers x and w by x @ w = 2^x/2^w, then (3 @ 1) @ 3 =

A. 2
B. 4
C. 8
D. 16
E. 32

x @ w = 2^x/2^w = 2^(x-y)
(3 @ 1) @ 3= (2^(3-1)) @3
=2^2@3
=4@3
=2^(4-3)
=2