If Ann saves x dollars each week and Beth saves y dollars each week, what is the total amount that they save per week?

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If Ann saves x dollars each week and Beth saves y dollars each week, what is the total amount that they save per week?

1) Beth saves $5 more per week than Ann saves per week
2) It takes Ann 6 weeks to save the same amount that Beth saves in 5 weeks

OA C
Source: — Data Sufficiency |

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Tue Mar 09, 2021 6:06 pm
Official Guide

If Ann saves x dollars each week and Beth saves y dollars each week, what is the total amount that they save per week?

1) Beth saves $5 more per week than Ann saves per week
2) It takes Ann 6 weeks to save the same amount that Beth saves in 5 weeks

OA C
Given: Ann saves x dollars each week and Beth saves y dollars each week

Statement 1: Beth saves $5 more per week than Ann saves per week
We can write: y = x + 5
Since this equation does not provide it sufficient information to find the value of x + y, statement 1 is NOT SUFFICIENT

Statement 2: It takes Ann 6 weeks to save the same amount that Beth saves in 5 weeks.
We can write: 6x = 5y
Since this equation does not provide it sufficient information to find the value of x + y, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
When we combine the two statements we get to the following system of equations:
y = x + 5
6x = 5y
Since we have two different linear equations with two variables, we COULD solve the system for x and y, which means we COULD answer the target question with certainty (although we would never waste precious time on test day actually calculating the value of x + y)

Since we COULD answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

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Brent
Brent Hanneson - Creator of GMATPrepNow.com
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