On a certain day it took Bill three times as long to drive

[BTGmoderatorLU]

Source: GMAT Prep

On a certain day, it took Bill three times as long to drive from home to work as it took Sue to drive from home to work. how many kilometers did Bill drive from home to work?

1) Sue drove 10 kilometers from home to work, and the ratio of distance driven from home to work time to drive from home to work was the same for Bill and Sue that day.
2) The ratio of distance driven from home to work time to drive from home to work for Sue that day was 64 kilometers per hour.

The OA is A

[Jay@ManhattanReview]

Source: GMAT Prep

On a certain day, it took Bill three times as long to drive from home to work as it took Sue to drive from home to work. how many kilometers did Bill drive from home to work?

1) Sue drove 10 kilometers from home to work, and the ratio of (distance driven from home to work) to (time to drive from home to work) was the same for Bill and Sue that day.
2) The ratio of (distance driven from home to work) to (time to drive from home to work) for Sue that day was 64 kilometers per hour.

Question edited

The OA is A

Say Sue drove x miles and took y hours, while Bill drove p miles; thus, he took 3*y = 3y hours

We have to get the value of p.

Let's take each statement one by one.

1) Sue drove 10 kilometers from home to work, and the ratio of (distance driven from home to work) to (time to drive from home to work) was the same for Bill and Sue that day.

=> x/y = p/3y => 10/y = p/3y => p = 30 miles. Suficient.

2) The ratio of (distance driven from home to work) to (time to drive from home to work) for Sue that day was 64 kilometers per hour.

=> x/y = 64. Can't get the value of p. Insufficient.

The correct answer: A

Hope this helps!

-Jay
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