BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

How many more CDs does Bea own than Al owns?

This topic has expert replies
Legendary Member
Posts: 2898
Joined: Thu Sep 07, 2017 2:49 pm
Thanked: 6 times
Followed by:5 members

How many more CDs does Bea own than Al owns?

by Vincen » Wed Sep 30, 2020 6:09 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

How many more CDs does Bea own than Al owns?

(1) If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns.

(2) If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs.

Answer: B

Source: Magoosh
Source: — Data Sufficiency |

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Vincen wrote:
Wed Sep 30, 2020 6:09 am
How many more CDs does Bea own than Al owns?

(1) If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns.

(2) If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs.

Answer: B

Source: Magoosh
Let A = number of CDs Al owns
Let B = number of CDs Bea owns

Target question: What is the value of B - A?

Statement 1: If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns.
We can create the equation: 2(B - 9) = A+9
Expand left side to get 2B - 18 = A+9
Rearrange to get: 2B - A = 27
This does not tell us the value of B - A.
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: If Bea gives 1 CD to Al, and Al purchases 4 additional CDs, then Al and Bea will have an equal number of CDs
We can create the equation: B - 1 = (A + 1) +4
Simplify this to get B - A = 6
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: B

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image