I agree with David.
For a question like that, you'd likely be given answer choices that show the calculations one would need to make in order to determine the interest.

Here's an example (from the 10th edition of the Official Guide) of such a question: https://www.beatthegmat.com/compound-int ... 72570.html

Cheers,
Brent

Hi emdadul28,

The GMAT would never give you a question that actually required such a heavy number of calculations to solve. That having been said, if you included the 5 answer choices, then there might be a way to answer this question WITHOUT having to do a lot of math - you might use estimation, eliminate answers as being too big or too small, use the 'rule of 72' or some other approach.

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