word problem

Question

Doug travels 4 times as fast as Eric. Traveling in opposite directions, they are 420 miles apart after 6 hours. Find their rates of travel.

Answer 1

We know that distance = rate x time

 

Let's say that Eric's rate is x. That means that Doug's rate can be represented by 4x.

 

Now, let's say that Doug traveled a distance of d. That means that Eric traveled a distance of (420 - d).

 

The time traveled by both individuals is 6 hours. 

 

For Doug, we have the equation:

 

d = (4x)(6) = 24x

 

For Eric, we have this equation:

 

420 - d = (x)(6)

 

We can replace d in Eric's equation with the value 24x. This gives us:

 

420 - 24x = 6x

 

420 = 30x

 

14 = x

 

Eric has a rate of travel of 14 mph. Doug has a rate of travel of 4 * 14 = 56 mph