For 2 variable rate problems, see Rate of Current or Wind Problems using 2 variables
PREALGEBRA RATE-TIME-DISTANCE PROBLEMS: Below are three videos with a basic introduction to rate-time-distance, especially appropriate for arithmetic or prealgebra, or for someone who does not know the formula.
Rate Time Distance - Basics 1: http://youtu.be/4WtSFt0uoFg
Rate Time Distance - Basics 2: http://youtu.be/nf0WFBFynBk
Rate Time Distance - Basics 3: http://youtu.be/dFSNx_bn7hk
These next two videos are more complicated examples showing how to compute the average rate of a trip when average speed changes part way through a trip. Uses the rate time distance formula d = rt. This is a more complicated example using the formula, but only prealgebra and knowledge of working with fractions and basic equations is needed.
Average Rate of Trip Example 1: http://youtu.be/IPa-Jq6RMsM
Average Rate of Trip Example 2: http://youtu.be/eSUWEczPUYo
ALGEBRA RATE-TIME-DISTANCE WORD PROBLEMS: Below is an introduction to and several Distance or Uniform Motion Problems which would be introduced in algebra classes. They are solved on the videos using one variable and a linear equation. These are also referred to as Rate-Time-Distance Problems, and use the formula R·T=D.
Rate-Time-Distance Intro: rt=d
This is an introduction to solving word problems on uniform motion (rate-time-distance) using the formula rate x time = distance, or rt=d. Six problems are introduced, and preliminary pictures are drawn. All problems are solved in the first six videos below.
http://www.youtube.com/watch?v=27yVkcVwNDU
Rate-Time-Distance Problem 1: http://youtu.be/SnrKIDv5RaM
Solves this word problem using uniform motion rt=d formula: Two cyclists start at the same corner and ride in opposite directions. One cyclist rides twice as fast as the other. In 3 hours, they are 81 miles apart. Find the rate of each cyclist. Answer: 9 mph and 18 mph
Rate-Time-Distance Problem 2: http://youtu.be/92fpYx8DQn8
Solves this word problem using uniform motion rt=d formula: A jogger started running at an average speed of 6 mph. Half an hour later, another runner started running after him starting from the same place at an average speed of 7 mph. How long will it take for the runner to catch up to the jogger? Answer: 3 hours
Rate-Time-Distance Problem 3: http://youtu.be/LCXlQDtCqnU
Solves this word problem using uniform motion rt=d formula: A 555-mile, 5-hour trip on the Autobahn was driven at two speeds. The average speed of the car was 105 mph on the first part of the trip, and the average speed was 115 mph for the second part. How long did the car drive at each speed? Answer: 105 mph for 2 hours and 115 mph for 3 hours
Rate-Time-Distance Problem 4: http://youtu.be/cL3sejFS8BM
Solves this word problem using uniform motion rt=d formula: Andy and Beth are at opposite ends of a 18-mile country road with plans to leave at the same time running toward each other to meet. Andy runs 7 mph while Beth runs 5 mph. How long after they begin will they meet? Answer: 1.5 hours
Rate-Time-Distance Problem 5: http://youtu.be/JH2iAMPIoRg
Solves this word problem using uniform motion rt=d formula: A car and a bus set out at 2 pm from the same spot, headed in the same direction. The average speed of the car is twice the average speed of the bus. After 2 hours, the car is 68 miles ahead of the bus. Find the rate of the bus and the car. Answer: Bus speed: 34 mph; Car speed: 68 mph
Rate-Time-Distance Problem 6: http://youtu.be/SxUOiwa6cxg
Solves this word problem using uniform motion rt=d formula: A pilot flew from one city to another city averaging 150 mph. Later, it flew back to the first city averaging 100 mph. The total flying time was 5 hours. How far apart are the cities? Answer: 300 miles
Rate-Time-Distance Problem 7: http://youtu.be/xdQWyqLQ9sU
Rate-Time-Distance Problem 8: http://youtu.be/7bqXgIfEyBQ
Rate-Time-Distance Problem 9: http://youtu.be/OVkIisYLdG0
Rate-Time-Distance Problem 10: http://youtu.be/_glUfwZXnUM
More Advanced Rate-Time-Distance Problems involving Rational Equations and Quadratic Equations.
These produce rational equations, and sometimes quadratic equations, so you'll need to know how to solve those kinds of problems to work those types in order to do this type.
Rate-Time-Distance Problem A