If wx = y, what is the value of xy?
Statement 1: wx^2 = 16
Statement 2: y = 4
Statement 1:
We need to find the answer of x*y. We know that y = wx. If you multiply wx (which is also equivalent to y) by x then you have wx^2. Therefore, wx^2 is equivalent to xy. Thereofre the value of xy is 16 according to statement 1. Statement 1 is sufficient.
Statement 2: y = 4. This does not provide us with any information about the value of x. We cannot determine the value of xy from this information. Therefore, this statement is insufficient.
Answer: A
GMAT PREP - Variables
This topic has expert replies
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Toph@GMAT_REBOOT
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vittalgmat
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I am little confused about this. I was hesitant to multiply both sides of stmt1 by x to wx^2 = xy. My reason being that we dont know anything about x, y or w. They could be +ve, -Ve, or 0.
Can u pls clarify where I can just multiply/divide by a variable (when the value of that var is not known) and where I cannot do it.
thanks
-V
Can u pls clarify where I can just multiply/divide by a variable (when the value of that var is not known) and where I cannot do it.
thanks
-V
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cramya
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I think this is not an inequality.(<,>,<=,>=) etc... If it is then u r correct.Can u pls clarify where I can just multiply/divide by a variable (when the value of that var is not known) and where I cannot do it.
wx=y (considering case when x is negative for eg)
w = 2 x = -4 y = -8
Multiply by x on bothe sides the equality remains the same
2 * -4 * -4 = 32
-8 * -4 = 32
Hope this helps and hope I dint miss something here!
--CR
