x, y and z are positive. If x percent of y is z, and z percent of x is y, then what is x² percent of 1/10?
A) 1/100
B) 1/10
C) 1
D) 10
E) 100
Answer: D
Source: www.gmatprepnow.com
Difficulty level: 600 - 650
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x, y and z are positive. If x percent of y is z
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Brent@GMATPrepNow
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regor60
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x percent of y is z: (X/100)*Y = Z
z percent of x is y: (Z/100)*X = Y
Therefore, (X/100)*X*(Z/100) = Z or X^2 = 10,000
and X = 100
what is x² percent of 1/10? : X^2 percent = (100*100/100) = 100 and 100 * (1/10) = D
z percent of x is y: (Z/100)*X = Y
Therefore, (X/100)*X*(Z/100) = Z or X^2 = 10,000
and X = 100
what is x² percent of 1/10? : X^2 percent = (100*100/100) = 100 and 100 * (1/10) = D
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DavidG@VeritasPrep
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Or we can do a little clever number-picking. Say x = 100, y = 100, and z = 100. (100% of 100 is surely 100, right?)Brent@GMATPrepNow wrote:x, y and z are positive. If x percent of y is z, and z percent of x is y, then what is x² percent of 1/10?
A) 1/100
B) 1/10
C) 1
D) 10
E) 100
Answer: D
Source: www.gmatprepnow.com
Difficulty level: 600 - 650
x² = 100² = 10,000
10,000% of 1/10 = 10,000*(1/100) *(1/10) = 100 *(1/10) = 10.
The answer is D
GMAT/MBA Expert
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Brent@GMATPrepNow
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- Joined: Mon Dec 08, 2008 6:26 pm
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Brent@GMATPrepNow wrote:x, y and z are positive. If x percent of y is z, and z percent of x is y, then what is x² percent of 1/10?
A) 1/100
B) 1/10
C) 1
D) 10
E) 100
Answer: D
Source: www.gmatprepnow.com
Difficulty level: 600 - 650
x percent of y is z
So (x/100)(y) = z
Simplify: xy/100 = z
z percent of x is y
So (z/100)(x) = y
Simplify: xz/100 = y
Multiply the two equations to get: (xy/100)(xz/100) = (z)(y)
Simplify: x²yz/10,000 = yz
Divide both sides by yz to get: x²/10,000 = 1
This means x² = 10,000
What is x² percent of 1/10?
In other words, (x²/100)(1/10) = ?
Replace x² with 10,000 to get: (10,000/100)(1/10) = 10,000/1,000 = 10
Answer: D
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
