Average Speed Problems

There are three main types of average problems commonly encountered in school algebra: Average (Arithmetic Mean), Weighted Average and Average Speed.

Average Speed Problems

Computation of average speed is a trickier type of average problems. Average speed uses the formula:

Example:

John drove for 3 hours at a rate of 50 miles per hour and for 2 hours at 60 miles per hour. What was his average speed for the whole journey?

Solution:

Step 1: The formula for distance is

Distance = Rate × Time
Total distance = 50 × 3 + 60 × 2 = 270

Step 2: Total time = 3 + 2 = 5

Step 3: Using the formula

Answer: The average speed is 54 miles per hour.

Be careful! You will get the wrong answer if you add the two speeds and divide the answer by two.

The following video gives another example of how to solve the average speed problem.

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