Last year the price per share of Stock X increased by *k* percent and the earnings per share of Stock X increased by *m* percent, where *k* is greater than *m*. By what percent did the ratio of price per share to earnings per share increase, in terms of *k* and *m*?

A. *k*/*m* %

B. (*k*–*m*) %

C. 100(*k*–*m*) / (100+*k*) %

D. 100(*k*–*m*) / (100+*m*) %

E. 100(*k*–*m*) / (100+*k*+*m*) %

**Correct Answer:** D

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You’ll find tons of practice questions, explanations for GMAT Official Guide questions, and strategies on our GMAT Question of the Day page.

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This is one of the most difficult questions in the GMAT universe. That said, there is a simple way to solve it that relies on a fundamental divisibility rule every GMAT studier should know:

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