\(2x + y\) years ago, Roberto was \(3x + y\) years old. How many years old was Roberto \(x\) years ago?

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

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

\(2x + y\) years ago, Roberto was \(3x + y\) years old. How many years old was Roberto \(x\) years ago?

A. \(x\)
B. \(4x + 2y\)
C. \(5x + 2y\)
D. \(6x + 2y\)
E. \(6x + y\)

Answer: B

Source: Magoosh
Source: — Problem Solving |

Legendary Member
Posts: 2499
Joined: Sun Oct 29, 2017 2:04 pm
Followed by:6 members
Vincen wrote:
Sat Jan 23, 2021 6:53 am
\(2x + y\) years ago, Roberto was \(3x + y\) years old. How many years old was Roberto \(x\) years ago?

A. \(x\)
B. \(4x + 2y\)
C. \(5x + 2y\)
D. \(6x + 2y\)
E. \(6x + y\)

Answer: B

Source: Magoosh
Before \(2x + y\) years ago:

\(3x + y\)

Now, \(2x + y\) years after

\(3x + y + 2x + y = 5x + 2y\)

Now, \(x\) years ago

\(5x + 2y -x = 4x + 2y \Longrightarrow\) B

GMAT/MBA Expert

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
Vincen wrote:
Sat Jan 23, 2021 6:53 am
\(2x + y\) years ago, Roberto was \(3x + y\) years old. How many years old was Roberto \(x\) years ago?

A. \(x\)
B. \(4x + 2y\)
C. \(5x + 2y\)
D. \(6x + 2y\)
E. \(6x + y\)

Answer: B

Source: Magoosh
Let R = Roberto's PRESENT age.
So, R - x = Roberto's age X YEARS AGO (this is our goal!)
Also, R - (2x + y) = Roberto's age (2x + y) YEARS AGO

2x + y years ago, Roberto was 3x + y years old.
We can write: R - (2x + y) = 3x + y
Remove brackets: R - 2x - y = 3x + y
Add y to both sides to get: R - 2x = 3x + 2y
Add x to both sides to get: R - x = 4x + 2y

Answer: B

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