GMAT Question of the Day - Problem Solving - Rate
Peter and Jane were both driving at 60mph down a certain highway heading south. At 3pm Peter crossed the border into Mexico and decreased his speed by 10mph. If Jane crossed the border into Mexico at 3:45pm, how many hours after crossing into Mexico will it take her to catch up with Peter?
GMAT Question of the Day Solution:
A rate T will be mighty helpful on this question. Take your time on GMAT word problems. Often they are not terribly complicated but it is easy to misinterpret the information throwing the whole approach into chaos.
First, read and understand the information. Then define what you are solving for. Lastly, use the details to fill in the blanks. This question is about relative rate - the rate at which Jane is catching up with Peter. In a chase scenario (one person stalking another) you subtract the rates. If people are headed towards each other (two cars crashing head on) you add the rates. This is the first scenario. Jane is trying to catch up with Peter. Here's an Official GMAT cooperative distance, work, and rate question to practice on: Pumps A, B, and C operate at their respective constant rates...
Here are another bunch of cooperative work and rate questions to practice on:
For more distance, work, and rate examples you can also check out our GMAT Question of the Day page