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100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## During the first two weeks of January, the total rainfall... tagged by: BTGmoderatorLU ##### This topic has 3 expert replies and 0 member replies ### Top Member ## During the first two weeks of January, the total rainfall... During the first two weeks of January, the total rainfall in Springdale was 15 inches. If the rainfall during the second week was 1.5 times the rainfall during the first week, what was the rainfall during the second week of January? A. 5 inches B. 6 inches C. 9 inches D. 10 inches E. 12 inches The OA is C. I'm really confused by this PS question. Experts, any suggestion about how can I solve this question? Thanks in advance. ### GMAT/MBA Expert Legendary Member Joined 14 Jan 2015 Posted: 2667 messages Followed by: 122 members Upvotes: 1153 GMAT Score: 770 LUANDATO wrote: During the first two weeks of January, the total rainfall in Springdale was 15 inches. If the rainfall during the second week was 1.5 times the rainfall during the first week, what was the rainfall during the second week of January? A. 5 inches B. 6 inches C. 9 inches D. 10 inches E. 12 inches The OA is C. I'm really confused by this PS question. Experts, any suggestion about how can I solve this question? Thanks in advance. Rain the first week: x Rain the second week: 1.5x Total = 15 x + 1.5x = 15 2.5x = 15 x = 6 Second week rainfall: 1.5x = 1.5 * 6 = 9. The answer is C _________________ Veritas Prep | GMAT Instructor Veritas Prep Reviews Save$100 off any live Veritas Prep GMAT Course

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### GMAT/MBA Expert

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Hi LUANDATO,

We're told that during the first two weeks of January, the TOTAL rainfall in Springdale was 15 inches and that the rainfall during the second week was 1.5 times the rainfall during the first week. We're asked for the rainfall (in inches) during the SECOND week of January. In these types of questions, it's likely that the total amount of rain for EACH week will be among the five answer choices, so you have to make sure to answer the question that is ASKED. In addition, when the 'numbers' involved are relatively small, you might find it fastest to simply 'brute force' the arithmetic until you answer the given question.

Since the rainfall in the second week is 1.5 times the rainfall in the first week, the possible TOTAL amounts of rain could be...
Wk 1. = 1 inch, Wk 2 = 1.5 inches, TOTAL = 2.5 inches
Wk 1 = 2 inches, Wk 2 = 3 inches, TOTAL = 5 inches
Etc.

Notice with the second example that the TOTAL is exactly 1/3 of what we need it to be. To save a few steps, we can now 'triple' each of those numbers....
Wk 1 = 6 inch, Wk 2 = 9 inches, TOTAL = 15 inches

And now we know how many inches it rained in the second week...

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

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Contact Rich at Rich.C@empowergmat.com

### GMAT/MBA Expert

GMAT Instructor
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LUANDATO wrote:
During the first two weeks of January, the total rainfall in Springdale was 15 inches. If the rainfall during the second week was 1.5 times the rainfall during the first week, what was the rainfall during the second week of January?

A. 5 inches
B. 6 inches
C. 9 inches
D. 10 inches
E. 12 inches
We can let the rainfall in the first week = a and the rainfall in the second week = b and create the following two equations:

a + b = 15

and

b = 1.5a

Substituting, we have:

a + 1.5a = 15

2.5a = 15

a = 6

Thus, the rainfall in the second week was 15 - 6 = 9 inches.

_________________

Scott Woodbury-Stewart
Founder and CEO
scott@targettestprep.com

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