ILULA08 wrote: ↑

Tue Aug 11, 2009 8:14 pm

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.

Solution:

Question Stem Analysis:

We need to determine the total amount Ann and Beth save each week, given that Ann saves x dollars each week and Beth saves y dollars each week. That is, we need to determine the value of x + y.

Statement One Alone:

This tells us that y = x + 5. However, without knowing the value of either x or y, we can’t determine the value of x + y. Statement one alone is not sufficient.

Statement Two Alone:

We see that 6x = 5y. However, without knowing the value of either x or y, we can’t determine the value of x + y. Statement two alone is not sufficient.

Statements One and Two Together:

With the two statements, we have two linear equations and two variables. Note that neither equation is dependent on the other, which means that one equation is not a linear multiple of the other. Thus, we can determine the values of x and y and hence the value of x + y. Both statements together are sufficient.

Answer: C