In the trapezoid above with height \(x,\) the sides with measures \(y\) and \(z\) are parallel. What is the area of the

This topic has expert replies
Legendary Member
Posts: 1622
Joined: Thu Mar 01, 2018 7:22 am
Followed by:2 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Trapezoid.png
In the trapezoid above with height \(x,\) the sides with measures \(y\) and \(z\) are parallel. What is the area of the trapezoid?

(1) \(z+y = \dfrac{20}{x}\)

(2) \(x=2\)

Answer: A

Source: Veritas Prep

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2621
Joined: Mon Jun 02, 2008 3:17 am
Location: Montreal
Thanked: 1090 times
Followed by:355 members
GMAT Score:780

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

One way to find the area of a trapezoid is to average the lengths of the parallel sides, then multiply that average by the height. Applying that here, the area we want to find is

[ (z +y)/2 ] * x

and now in Statement 1, if we multiply both sides by x, and divide both sides by 2, the left side will look exactly like the expression above:

z + y = 20/x
(z + y)(x) = 20
[(z + y)/2] * x = 10

so Statement 1 is sufficient. Statement 2 is clearly insufficient, so the answer is A.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com