# Average Speed

Pro Problems > Math > Algebra > Equations > Word Problems > Linear > Rate and Time## Average Speed

John drove at 20 mph for 30 minutes, and then he drove back home at 10 mph. What was his average speed for the entire trip?

## Solution

In order to make it feasible for teachers to use these problems in their classwork, no solutions are publicly visible, so students cannot simply look up the answers. If you would like to view the solutions to these problems, you must have a Virtual Classroom subscription.## Similar Problems

### Building a Wall

If Jameson can build a 20 foot wall in 6 hours, and Jaqueline can build a 50 foot wall in 12 hours, and the two of them work together to build a 180 foot wall (with each of them starting at opposite ends of the wall), how much wall will each build before the wall is complete?

### Traveling to the City

A car travels from city A to city B in 12 hours. It then travels from city B to city C at the same speed, in 8 hours. If the car was traveling 5 mph faster, it would have traveled from city A to city B in 10 hours. What is the distance from city B to city C?

### Monkey in the Middle

Geoge the Monkey can run at a speed of 12 mph. Hazel can walk at a rate of 4 mph, and Henrietta can walk at a rate of 2 mph.

George is standing halfway between Hazel and Henrietta, who are 1,320 feet apart, and begin walking toward each other.

At the moment they begin walking, George begins running toward Hazel. When he reaches her, he turns around and runs to Henrietta. Upon reaching her, he turns around again, and continues on like this, until the two girls meet, and he is sandwiched between them.

How far did George run?

### A Long Walk

Marco walks a certain distance at a certain speed (measured in miles per hour), and then returns over the same distance at a speed one mph less than his original walking speed. He took a total of 35 hours. If, instead of slowing down for his return journey, he had sped up by one mph, his journey would have taken 27 hours. How far did he walk?

### Daylight Savings Time

A clock adjusts its timing each night by contacting a satellite at 2:00 AM to find out the official standard time. Since it has a mechanical action with physical minute, second and hour hands, if the clock finds out it is out of sync, it will move at 12 times normal speed in order to "catch up" with the actual time. (If it is ahead of the correct time, it will still move forward, until it wraps around to the correct time.)

In the fall, when Daylight Savings Time happens, at 2:00 the satellite tells the clock that it is actually 1:00. Thus, the clock has to move forward at high speed until it wraps around to the correct time.

How long will it take the clock to be displaying the correct time again?

### Waiting for Christmas

My son said, "Daddy, I can't wait for Christmas. How long is it until Christmas?"

I told him, "The number of days left until Christmas is 30 more than the number of weeks until Christmas."

What day is it?

### Birds of a Feather

Three birds are named Billie, Millie, and Willie. Billie flies twice as fast as Millie, who flies a third as fast as Willie. If Billie and Millie have a race, and Willie arrives at the finish when Billie has 12 miles more to travel, what was the race distance?

### Fast Reader

I have four books, each with n pages, and I can read them all in four hours.

I have four more books, each with each 120 fewer pages than my original four books. I can read them all in three hours.

I have five more books, each with 120 more pages than my original four books. How long would it take me to read all five books?

### City A to City B

A car can travel from city A to city B in 8 hours. If its speed during the return journey was decreased by 7 mph, it would take 9 hours to get back to city A. How far apart are the two cities?

### Arrival Time

Two trains are traveling from Washington DC to Bangor, ME. The first train leaves Washington DC and travels to Boston, MA (430 miles) and has a two hour stop before continuing on to Bangor (250 miles).

The second train leaves Washington DC one and a half hour later than the first train. It travels by way of Albany, NY (338 miles) and then continues directly on to Bangor (400 miles).

If the first train travels at 34 mph, how fast does the second train have to travel to reach Bangor at the same time as the first train?