BTGmoderatorLU wrote:Source: Princeton Review

Derek's cell phone bill shows total minutes used for each of two categories: peak minutes and off-peak minutes. If Derek used a total of 75 minutes last month, how many off-peak minutes did he use?

1) Derek used twice as many off-peak minutes as peak minutes last month.
2) Last month, Derek exceeded his allowance of off-peak minutes by 25 percent.

The OA is A

Given: Derek's cell phone bill shows total minutes used for each of two categories: peak minutes and off-peak minutes. Derek used a total of 75 minutes last month.

We have to determine the number of off-peak minutes he used.

Let's take each statement one by one.

1) Derek used twice as many off-peak minutes as peak minutes last month.

Say the number of peak minutes used = x, thus, the number of off-peak minutes used = 2x;

Thus, x + 2x = 75 => x = 24 minutes. Sufficient.

2) Last month, Derek exceeded his allowance of off-peak minutes by 25 percent.

Insufficient since we do not know his allowance of off-peak minutes.

The correct answer: A

Hope this helps!

-Jay
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