how to setup equation?

Question

two runners, ken and devon, leave home at the same time and jog in different directions. ken travels east at a pace which is 4 miles per hour faster than devon, who is traveling west. after two hours they are 28 miles apart. find the speed of each runner.

 

how would i set up equation?

Answer 1

D = RT

 

<--------| 28 |-------->

     R(2)           (R+4)(2)

 

Thus,

 

2r + 2r + 8 = 28

 

4r + 8 = 28

 

4r = 20

 

r = 5 mph (Devon)

 

r + 4 = 9 mph (Ken)