GMAT Official Guide Quantitative Review 2019_ Book

GMAT® Official Guide 2019 Quantitative Review

Geometry; Algebra

Since MPQT is a square, let MP= PQ = x. Then

PR= PQ + QR= x + 12. The area of MPRS can

be expressed as x(x + 12). Since the area of MPRS

is given to be 540,

x(x + 12) = 540

x^2 +l2x = 540

x^2 + 12x-540 = 0

(x-18)(x+30)=0

x=18 orx=-30

Since x represents a length and must be positive,

x = 18. The area of TQRS is then (12)(18) = 216.

As an alternative to solving the quadratic

equation, look for a pair of positive numbers such

that their product is 540 and one is 12 greater

than the other. The pair is 18 and 30, so x = 18

and the area of TQRS is then (12)(18) = 216.

The correct answer is B.

PS09439

131. A certain manufacturer sells its product to stores
     in 113 different regions worldwide, with an average
     (arithmetic mean) of 181 stores per region. If last
     year these stores sold an average of 51,752 units
     of the manufacturer's product per store, which of the
     following is closest to the total number of units of the
     manufacturer's product sold worldwide last year?

(A) 106

(B) 107

(Cl 108

(Dl 109

(E) 1010

Arithmetic

(113)(181)(51, 752) "'"(100)(200)(50,000)

=10^2 x(2x10^2 )x(5x10^4 )

= (2X 5) X 102 +^2 +^4

= 10^1 X 108 = 10^9

The correct answer is D.

PSJ.7708

132. Andrew started saving at the beginning of the year and
     had saved $240 by the end of the year. He continued
     to save and by the end of 2 years had saved a total of
     $540. Which of the following is closest to the percent
     increase in the amount Andrew saved during the
     second year compared to the amount he saved during
     the first year?

(Al 11%

(Bl 25%

(C) 44%

(D) 56%

(E) 125%

Arithmetiic

Andrew saved $240 in the first year and

$540 -$240 = $300 in the second year. The

percent increase in the amount Andrew saved

in the second year compared to the amount he

(

saved in the first year is ----^300 -^240 X 100 )o Yo =

240

( 2

6

:0 X 100) % = ( ¼ X 100) % = 25%.

The correct answer is B.

PS! 9062

133. Two numbers differ by 2 and sum to S. Which of the
     following is the greater of the numbers in terms of S?

(A) -s -1

2

(B) s

2

(C) -+-s^1

2 2

(D) - + s 1

2

(El 2+2 s

Algebra r~t-d0. rPP f'QlPf c n.

Let x represent the greater of the two numbers

that differ by 2. Then, x - 2 represents the lesser

of the two numbers. The two numbers sum to

S, so x + (.x -2) = S. It follows that 2x - 2 = S, or

s

2x = S + 2, or x = - + l.

2

The correct answer is D.