Lesson: Data Sufficiency Challenging - 16t05

Easy Math/Tough Applications: Example 1

Challenging questions in the Quantitative Section may test your ability to cut through dense information to get to the heart of what often turns out to be a relatively simple matter. Why does the Exam do this? To see whether you have the ability to whittle complex language down to an easy solution. In these problems, the important thing is to find the "question behind the question." That is, to find what the question is really asking. Here’s an example:

At the end of every hour a culture of bacteria becomes some number of times larger than it was the previous hour. If the number of bacteria was originally greater than 1 and if the rate of growth also increases every hour, what was the original number of bacteria?

1) of the original culture would have resulted in a total of 385 bacteria after 3 hours.

2) The original number of bacteria was less than 4.

Review the question stem above. Do you recognize the math concept that this is testing? Type it into the Text Box, and click Continue.

This problem is really about .

Review Statement 1 below. Is it sufficient or insufficient? Select the correct answer and then click Continue.

1) of the original culture would have resulted in a total of 385 bacteria after 3 hours.?

Sufficient

Insufficient

Review Statement 2 below. Is it sufficient or insufficient? Select the correct answer and then click Continue.

2) The original number of bacteria was less than 4.

Sufficient

Insufficient

The question is asking for the (exact) original number, not just a range. You know from the stem that the original number was greater than 1, so it could have been either 2 or 3, which is still insufficient.

Countinue

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