Megan and David are jogging around a square p… | GMAT Sprint

Free Practice Question

PS · Problem Solving

655-705

Work Rate Problems

Megan and David are jogging around a square park. Megan completes one lap in 1 minute, while David takes 1 minute and 24 seconds for the same distance. If both burn 30 calories per lap, how long will it take for Megan to burn 150 calories more than David?

Correct answer marked below

10 minutes 40 seconds

17 minutes 30 seconds

Correct

20 minutes 24 seconds

21 minutes 12 seconds

A unique value cannot be determined

You can see the correct answer above. Sign in for free to unlock the complete worked solution.

Get detailed analytics, unlock full explanations, and move up difficulty tiers as you practice.

Explanation

Preview

Official Explanation

Official

For Megan to burn

150

calories more than David, she needs to run

\frac{150}{30}=5

laps extra. The speed of Megan is

= 1

, and the speed of David is

= \frac{1}{1.4}

. Let Megan run five laps more than David in time

t

. This can be expressed as…

Comments

Be the first to share your thoughts and help others understand it better.

What this question tests

Your ability to combine individual work rates, usually by working with the fraction of a job completed per unit of time.

Adding the times instead of the rates, or forgetting to take the reciprocal when combining rates.