• NEW! FREE Beat The GMAT Quizzes
Hundreds of Questions Highly Detailed Reporting Expert Explanations
• 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 PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote How many coins This topic has 3 expert replies and 1 member reply How many coins If 378 coins consist of dollars, 50 cent and 25 cent coins whose values are in the ratio of 13 : 11 : 7, the number of 50 cent coins will be (A) 128 (B) 132 (C) 133 (D) 136 (E) 138 OE: B Top Member Legendary Member Joined 03 Feb 2014 Posted: 2070 messages Followed by: 133 members Upvotes: 955 GMAT Score: 800 For the same value of 1 dollar you need 2 50 cent coins or 4 25 cent coins. Since we are looking for an answer in terms of number of coins, convert the value ratio to a number of coins ratio. Dollars remains the same. 13 To get the 50 cent coins ratio number, multiply 11 by 2. 22 To get the 25 cent coins ratio number, multiply 7 by 4. 28 So the coins ratio is 13:22:28. Add the numbers in the ratio to get a total divisor for 378. 13 + 22 + 28 = 63 To find out how many times the ratio has to be multiplied to show the exact number of each type of coin, divide. 378/63 = 6 Calculate the number of 50 cent coins. 6 x 22 = 132 The correct answer is B. _________________ Marty Murray GMAT Coach m.w.murray@hotmail.com https://infinitemindprep.com/ In Person in the New York Area and Online Worldwide GMAT/MBA Expert Legendary Member Joined 14 Jan 2015 Posted: 2667 messages Followed by: 122 members Upvotes: 1153 GMAT Score: 770 coolhabhi wrote: If 378 coins consist of dollars, 50 cent and 25 cent coins whose values are in the ratio of 13 : 11 : 7, the number of 50 cent coins will be (A) 128 (B) 132 (C) 133 (D) 136 (E) 138 OE: B If the value of the 50-cent coins is a multiple of 11, the number of 50-cent coins must also be a multiple of 11. (If you had$11 worth of 50-cent coins, you'd have 22 coins. If you had $22 worth of 50-cent coins you'd have 44 coins, etc.) Look at the answers. The only multiple of 11 is B _________________ Veritas Prep | GMAT Instructor Veritas Prep Reviews Save$100 off any live Veritas Prep GMAT Course

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

GMAT Instructor
Joined
12 Sep 2012
Posted:
2635 messages
Followed by:
116 members
625
Target GMAT Score:
V51
GMAT Score:
780
Another approach:

Let's say we have x half dollars.

Since dollars are worth twice as much, we have (1/2) * (13/11) * x of them. ((1/2) for the double value, (13/11) for the ratio of dollars to half dollars.)

Since quarters are worth half as much, we have 2 * (7/11) * x of them.

x + (13/22)x + (14/11)x = 378

x = 132

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

GMAT Instructor
Joined
12 Sep 2012
Posted:
2635 messages
Followed by:
116 members
625
Target GMAT Score:
V51
GMAT Score:
780
I do think David's approach is the way this is meant to be solved, though. The answers only have one multiple of 11, which can't be a coincidence, and any computational approach is meant to punish you for not looking for the Easter egg hidden in the answers.

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!
• 5-Day Free Trial
5-day free, full-access trial TTP Quant

Available with Beat the GMAT members only code

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to $200 Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• Get 300+ Practice Questions

Available with Beat the GMAT members only code

Top First Responders*

1 Jay@ManhattanReview 67 first replies
2 Brent@GMATPrepNow 64 first replies
3 GMATGuruNY 44 first replies
4 Ian Stewart 23 first replies
5 Scott@TargetTestPrep 17 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

211 posts
2 Max@Math Revolution

Math Revolution

94 posts
3 Brent@GMATPrepNow

GMAT Prep Now Teacher

90 posts
4 GMATGuruNY

The Princeton Review Teacher

69 posts
5 Jay@ManhattanReview

Manhattan Review

68 posts
See More Top Beat The GMAT Experts