Question in-200

3.2 Percentages - Successive percent changes
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In 2008, Zinah earned 14% more than in 2007, and in 2009 Zinah earned 4% more than in 2008. If Zinah earned y times as much in 2009 as in 2007, what is the value of y ?

A.

0.5600

B.

1.0056

C.

1.1800

D.

1.1856

In 2008 , Zinah earned 14 % more than in 2007 , and in 2009 Zinah

Hard-difficulty · SAT Math · Percentages — Successive percent changes. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

Choice D is correct. It’s given that in 2008 Zinah earned 14% more than in 2007. Let h represent the amount Zinah earned in 2007 and let j represent the amount that Zinah earned in 2008. This situation can be represented by the equation j=1+14100h, or j = 1.14 h . It’s also given that in 2009 Zinah earned 4% more than in 2008. Let k represent the amount Zinah earned in 2009. This situation can be represented by the equation k=1+4100j, or k=1.04j. Substituting 1.14 h for j in the equation k=1.04j yields k=1.041.14h, or k = 1.1856 h . If Zinah earned y times as much in 2009 as in 2007, then the value of y is 1.1856 .

Choice A is incorrect and may result from conceptual or calculation errors.

Choice B is incorrect and may result from conceptual or calculation errors.

Choice C is incorrect and may result from conceptual or calculation errors.