proportion question

Expert replies

datonman: Senior | Next Rank: 100 Posts; Posts: 53; Joined: Wed May 28, 2014 9:36 pmFollowed by: 1 member

by datonman » Sat Oct 31, 2015 4:56 pm

Three investors, A, B, and C, divide the profits from a business enterprise in the ratio of 5:7:8, respectively. If investor A earned $3,500, how much money did investors B and C earn in total?

A.)$4,000
B.)$4,900
C.)$5,600
D.)$9,500
E.)$10,500

From what I can understand is that the answer is given as 5+7+8=20. Investor A has 5 of these shares and Investors B and C are left with 20-5=15 profit shares. 15 is 3 times 5 and investors B and C earned three times that of Investor A. Thus, $3,500 X 3 = 10,500.

My problem is how did B and C receive 'three' times that of Investor A? (20-5=15?)

Like this post

Source: Beat The GMAT — Problem Solving | Sat Oct 31, 2015 4:56 pm

theCEO: Master | Next Rank: 500 Posts; Posts: 363; Joined: Sun Oct 17, 2010 3:24 pmFollowed by: 3 members; Thanked: 115 times

by theCEO » Sat Oct 31, 2015 5:29 pm

datonman wrote:Three investors, A, B, and C, divide the profits from a business enterprise in the ratio of 5:7:8, respectively. If investor A earned $3,500, how much money did investors B and C earn in total?

A.)$4,000
B.)$4,900
C.)$5,600
D.)$9,500
E.)$10,500

From what I can understand is that the answer is given as 5+7+8=20. Investor A has 5 of these shares and Investors B and C are left with 20-5=15 profit shares. 15 is 3 times 5 and investors B and C earned three times that of Investor A. Thus, $3,500 X 3 = 10,500.

My problem is how did B and C receive 'three' times that of Investor A? (20-5=15?)

A:B:C = 5:7:8

A shares = total shares x 5/(5+7+8)= total shares x 5/20
B+C shares = total shares x (7+8)/(5+7+8) = total shares x 15/20

B+C shares / A shares = (total shares x 15/20) / (total shares x 5/20)
B+C shares / A shares = (15/20) / (5/20) = (3/4) / (1/4) = 3/4 * 4/1 = 3

Therefore B+C received 3 times what A received = 3x3500 = 10500
ans = e

Like this post

GMAT/MBA Expert

[email protected]: Elite Legendary Member; Posts: 10392; Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members; Location: Palo Alto, CA; Thanked: 2867 times; GMAT Score:800

by [email protected] » Sun Nov 01, 2015 11:12 am

Hi datonman,

There are a variety of different ways to deal with ratio-based questions.

From the prompt, we know that Investor A received some 'multiple of 5' dollars. Once we're told that Investor A received $3500, we can figure out what that multiple is (3500/5 = 700). This means that Investor B received 7(700) = $4900 and Investor C received 8(700) = $5600.

B+C = $10,500 - this is 3 times $3500.

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

Contact Rich at [email protected]

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review