Thursdays With Ron: How to Solve Rate/Distance Problems

by Manhattan Prep, May 20, 2010

We're always happy to share strategy for how to improve on the GMAT, and one way we do so is with our Thursdays with Ron series. Every other Thursday, our instructor Ron Purewal (known on the Beat the GMAT forums as lunarpower) hosts a free study hall session, where anyone can submit questions ahead of time and attend. Ron chooses a few themes from the questions he gets and goes over strategies for them.

In the following recording, Ron describes a method for solving "RTD" problems: problems that have to do with rate and distance (and other problems that take the same form.) He outlines a seven step process for this, which you can watch below.

This is the problem Ron uses as an example in the video:

A Hiker walked for two days. On the second day the hiker walked 2 hours longer and at an average speed 1 mile per hour faster than he walked on the first day. If during the two days he walked a total of 64 miles and spent a total of 18 hours walking, what was his average speed on the first day?

Here's an outline of Ron's steps, with the minute markers for each step in parenthesis. Make sure to watch the video, though, so that you're able to follow along!

Step 1 (1:30): Create a chart with the equation on top, and with one row for each situation.

Step 2 (4:45): Fill in your chart with the hard numbers: numbers that should go into the spaces in the chart. Make sure not to put relationships in the chart yet.

Step 3 (8:28): Find the relationships between the unknown quantities in the problem and write them out - with words, not equations or numbers - on a separate row in the chart.

Step 4 (12:18): Define one variable, based on a relationship you've identified.

Step 5 (13:51): Fill in the rows of the chart, using the equation on the top of the chart.

Step 6 (14:50): Take the leftover relationship from your chart and write an equation.

Step 7 (15:43): Solve the equation.

If you want to view recordings of past Thursdays with Ron or submit questions for the next live session, which takes place on May 27, you can do so here.