Last year, sales at Company X

[NandishSS]

Last year, sales at Company X were 10% greater in February than in January, 15% less in March than in Feb, 20% greater in April than in March, 10% less in May than in April, and 5% greater in June than in May. In which month were sales closest to Jan?

A. Feb
B. Mar
C. Apr
D. May
E. June

OA:D

Source-GMATPrep EP2

[GMATGuruNY]

Last year, sales at Company X were 10% greater in February than in January, 15% less in March than in Feb, 20% greater in April than in March, 10% less in May than in April, and 5% greater in June than in May. In which month were sales closest to Jan?

A. Feb
B. Mar
C. Apr
D. May
E. June

Let Jan = 100.
Since Feb is 10% greater than Jan, Feb = 100 + (10% of 100) = 100 + 10 = 110.
Since Mar is 15% less than Feb, Mar = 110 - (15% of 110) ≈ 110 - 16 = 94.
Since Apr is 20% more than Mar, Apr = 94 + (20% of 94) ≈ 94 + 19 = 113.
Since May is 10% less than Apr, May = 113 - (10% of 113) ≈ 113 - 11 = 102.
Since Jun is 5% greater than May, Jun > 102.

As indicated by the portion in blue, May's sales (102) are closest to January's (100).

The correct answer is D.

[[email protected]]

Hi NandishSS,

TESTing VALUES (the approach used by Mitch) works perfectly in these types questions. You can also approach these types of questions algebraically (you just have to be careful with the 'math work').

January = X dollars in sales
February = 1.1X dollars in sales
March = 1.1X - (.15)(1.1X) = 1.1X - .165X = .935X dollars in sales
April = .935X + (.2)(.935X) = 1.122X dollars in sales
May = 1.122X - (.1)(1.122X) = 1.0098X dollars in sales
June = 1.0098X + .(.05)(1.0098X) = clearly more than the dollar sales in May

We're asked for the month that was closest to January in sales (so closer to X). That is clearly May.

Looking at this work, you should be able to see how TESTing VALUES is an easier approach.

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

[Jay@ManhattanReview]

Last year, sales at Company X were 10% greater in February than in January, 15% less in March than in Feb, 20% greater in April than in March, 10% less in May than in April, and 5% greater in June than in May. In which month were sales closest to Jan?

A. Feb
B. Mar
C. Apr
D. May
E. June

OA:D

Source-GMATPrep EP2

Say sales in Jan = $100

Given that Feb sale is 10% greater than Jan sale, Feb sale = 110% of 100 = 110.
Given that Mar sale is 15% less than Feb sale, Mar sale = 85% of 110 ≈ 94.
Given that Apr sale is 20% more than Mar sale, Apr sale = 120% of 94 ≈ 113.
Given that May sale is 10% less than Apr sale, May sale = 90% of 113 ≈ 102.
Given that Jun sale is 5% greater than May sale, Jun sale = 105% of 102 ≈ 107.

We see that May's sale (102) is closest to Jan sale (100).

OA: D

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Vienna | Kuala Lumpur | Sydney | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.