swerve wrote:If 37.5% of the 880 students at a certain college are enrolled in biology classes, how many students at the college are NOT enrolled in a biology class?

A. 110
B. 330
C. 550
D. 430
E. 880

We can actually solve this question without doing any calculations. Instead, we'll just use a little number sense.

37.5% is less than 1/2.
So, if LESS THAN half of the 880 students ARE enrolled in biology, we can conclude that MORE THAN half of the 880 students are NOT enrolled in biology.
Half of 880 is 440, so we're looking for an answer choice that's GREATER THAN 440

This leaves C or E.
Of course, E makes no sense, so the correct answer must be C

Cheers,
Brent

Hi swerve,

We're told that 37.5% of the 880 students at a certain college are enrolled in biology classes. We're asked for the number of students at the college are NOT enrolled in a biology class. The answer choices to this question are 'spread out' enough that we can answer it with estimation.

37.5% can be 'rounded' to 1/3
880 can be 'rounded' to 900

1/3 of 900 is 300, so approximately 300 of the students are enrolled in biology classes. This means that 880 - 300 = 580 are NOT enrolled in biology classes. There's only one answer that's close to 580...

Final Answer: C

GMAT assassins aren't born, they're made,
Rich