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Word Problems

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by swerve » Wed Mar 10, 2021 10:37 am

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B

C

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E

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\(2x+y\) 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. \(6x+y\)

The OA is B

Source: Magoosh
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Source: — Problem Solving |

Re: Word Problems

by Brent@GMATPrepNow » Thu Mar 11, 2021 10:50 am
swerve wrote:
Wed Mar 10, 2021 10:37 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. \(6x+y\)

The OA is 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
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