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: (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

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 Or we can do a little clever number-picking. Say x = 100, y = 100, and z = 100. (100% of 100 is surely 100, right?) x² = 100² = 10,000 10,000% of 1/10 = 10,000*(1/100) *(1/10) = 100 *(1/10) = 10. The answer is D

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