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If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y

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If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y [#permalink] If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y   12 Nov 2020, 06:05
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If \(x^y = 16\), find x?

(1) y = 4
(2) |x*y| > x*y


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C
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Re: If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y [#permalink] If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y   12 Nov 2020, 08:56
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GMATinsight wrote:
if \(x^y = 16\), find x?

1) y = 4
2) |x*y| > x*y

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There can be numerous values fitting in for x and y. We don’t even know that x and y are integers.

1) y=4
\(x^y=x^4=16=2^4=(-2)^4\), so x can be 2 or -2.
Insufficient

2) |x*y|>x*y
x*y has to be negative for this, that is xy<0.
This means at least one of x or y is negative. Nothing more.
Insufficient

Combined
x has to be -2 as y is 4 and x<0.
Sufficient

C
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Re: If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y [#permalink] If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y   12 Nov 2020, 11:16
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GMATinsight wrote:
If \(x^y = 16\), find x?

(1) y = 4
(2) |x*y| > x*y


Source: https://www.GMATinsight.com

Join my Youtube for free Videos on GMAT prep


target find value of x in \(x^y = 16\)
#1
y=4
value of x can be +/-2
insufficient
#2
|x*y| > x*y
value of x or y has to be -ve as x^y = 16
from 1 &2
we can say that x= -2 and y = 4
sufficient
option C
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Re: If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y [#permalink] If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y   13 Nov 2020, 00:52
If \(x^y\)=16, find x?

Step 1: Understanding statement 1 alone
(1) y = 4
Even power hides the sign of the base, hence x can be -2 or 2
Insufficient

Step 2: Understanding statement 2 alone
(2) |x*y| > x*y
Product of x and y is negative
When x = -2, y = 4
When x = -4, y =2
Insufficient

Step 3: Combining
y = 4 and product of x and y is negative, hence x is negative; x = -2
Sufficient

C is correct
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Re: If x^y = 16, find x? (1) y = 4 (2) |x*y| > x*y [#permalink]
13 Nov 2020, 00:52
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