sanju09 wrote: ↑

Fri Aug 27, 2010 5:31 am

Of the 230 single-family homes built in City X last year, how many were occupied at the end of the year?

(1) Of all single-family homes in City X, 90 percent were occupied at the end of last year.

(2) A total of 7,200 single-family homes in City X were occupied at the end of last year.

Solution:

Question Stem Analysis:

We need to determine the number of the 230 single-family homes built in City X last year that were occupied at the end of the year.

Statement One Alone:

Even though we know 90% of all single-family homes were occupied at the end of last year, we don’t know the number of the 230 newly-built single-family homes that were occupied at the end of the year. It’s possible that all 230 were occupied, none of them were occupied, or some of them were occupied. Statement one alone is not sufficient.

Statement Two Alone:

Even though we know 7,200 single-family homes were occupied at the end of last year, we don’t know the number of the 230 newly-built single-family homes that were occupied at the end of the year. It’s possible that all 230 were occupied, none of them were occupied, or some of them were occupied. Statement two alone is not sufficient.

Statements One and Two Together:

From the two statements, we can determine there were a total of 7,200/0.9 = 8,000 single-family homes in City X last year. However, we still can’t determine the number of the 230 newly-built single-family homes that were occupied at the end of the year. It’s possible that all 230 were occupied, none of them were occupied, or some of them were occupied. Both statements are not sufficient.

Answer: E