• NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    Hundreds of Questions Highly Detailed Reporting Expert Explanations TAKE A FREE GMAT QUIZ
  • 7 CATs FREE!
    If you earn 100 Forum Points

    Engage in the Beat The GMAT forums to earn
    100 points for $49 worth of Veritas practice GMATs FREE

    Veritas Prep
    VERITAS PRACTICE GMAT EXAMS
    Earn 10 Points Per Post
    Earn 10 Points Per Thanks
    Earn 10 Points Per Upvote
    REDEEM NOW

During the first two weeks of January, the total rainfall...

This topic has 3 expert replies and 0 member replies

During the first two weeks of January, the total rainfall...

Post
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.

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Legendary Member
Joined
14 Jan 2015
Posted:
2667 messages
Followed by:
122 members
Upvotes:
1153
GMAT Score:
770
Post
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

  • +1 Upvote Post
  • Quote
  • Flag
Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

GMAT/MBA Expert

Elite Legendary Member
Joined
23 Jun 2013
Posted:
10197 messages
Followed by:
496 members
Upvotes:
2867
GMAT Score:
800
Post
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...

Final Answer: C

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

_________________
Contact Rich at Rich.C@empowergmat.com

  • +1 Upvote Post
  • Quote
  • Flag
Post
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.

Answer: C

_________________

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



See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

  • +1 Upvote Post
  • Quote
  • Flag
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • The Princeton Review
    FREE GMAT Exam
    Know how you'd score today for $0

    Available with Beat the GMAT members only code

    MORE DETAILS
    The Princeton Review
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh

Top First Responders*

1 Brent@GMATPrepNow 43 first replies
2 Ian Stewart 35 first replies
3 Jay@ManhattanReview 32 first replies
4 GMATGuruNY 27 first replies
5 Scott@TargetTestPrep 13 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 image description Scott@TargetTestPrep

Target Test Prep

189 posts
2 image description Max@Math Revolution

Math Revolution

90 posts
3 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

75 posts
4 image description GMATGuruNY

The Princeton Review Teacher

44 posts
5 image description Ian Stewart

GMATiX Teacher

42 posts
See More Top Beat The GMAT Experts