IMO E
(1) tell sus that xy is 4. But if you expand (x - y)^4 it would give powers of x and y independently which cannot be solved as x and y can be anything, integers or decimalshence insuff
(2) tells us that x and y are integers. But does not give any values so insuff
combining we get x and y values to be either 1 and 7 or -1 and 0-7 and in either cases give the value so suff
Value of (x-y)^4
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Source: Beat The GMAT — Data Sufficiency |
The answer is C.
1. The product of X & Y is 7. Not sufficient. As X=0.01, Y=700 or X=0.1, Y=70 producing different results for (X-Y)^4
2. X & Y are integers; Not sufficient to arrive at single results for (X-Y)^4.
Combinging both -
XY = 7
=> X = 1, Y =7
=> X = -1, Y = -7
=> X = 7, Y = 1
=> X = -7, Y = -1
All result into 6^4.
Thus answer is C.
1. The product of X & Y is 7. Not sufficient. As X=0.01, Y=700 or X=0.1, Y=70 producing different results for (X-Y)^4
2. X & Y are integers; Not sufficient to arrive at single results for (X-Y)^4.
Combinging both -
XY = 7
=> X = 1, Y =7
=> X = -1, Y = -7
=> X = 7, Y = 1
=> X = -7, Y = -1
All result into 6^4.
Thus answer is C.
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raghavsarathy
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When both are negative , (-1 - (-7) )^4 which is 6^4ogbeni wrote:I'm kinda confused
How does (1-7)^4 = (-1-7)^4?
The answer should be E because combining both statements does not give one value for (x-y)^4. Please show me what I'm missing.
So we get the same value
