Distance Word Problems - Given the Total Time

Distance problems are word problems that involve the distance an object will travel at a certain average rate for a given period of time.

The formula for distance problems is: distance = rate × time or d = r × t.

Things to watch out for:
Make sure that you change the units when necessary. For example, if the rate is given in miles per hour and the time is given in minutes then change the units appropriately.

It would be helpful to use a table to organize the information for distance problems. A table helps you to think about one number at a time instead being confused by the question.

Distance Problems: Given Total Time

Example:
John took a drive to town at an average rate of 40 mph. In the evening, he drove back at 30 mph. If he spent a total of 7 hours traveling, what is the distance traveled by John?

Solution:
Step 1: Set up a rtd table.

Step 2: Fill in the table with information given in the question.

John took a drive to town at an average rate of 40 mph. In the evening, he drove back at 30 mph. If he spent a total of 7 hours traveling, what is the distance traveled by John?

Let t = time to travel to town.

7 – t = time to return from town.

Step 3: Fill in the values for d using the formula d = rt

Step 4: Since the distances traveled in both cases are the same, we get the equation:

40t = 30(7 – t)

Use distributive property

40t = 210 – 30t

Isolate variable t

40t + 30t = 210

70t = 210

Step 5: The distance traveled by John to town is

40t = 120

The distance traveled by John to go back is also 120

So, the total distance traveled by John is 240

Answer: The distance traveled by John is 240 miles.

The following video shows another example of a distance-time word problem where the total time is given.

Custom Search