SOLUTION: Two trucks leave from the same truck stop at the same time. One travels east on interstae 80 and the other travels west. The eastbound truck averages 40 miles per hour, and the wes

There are two ways to do this problem,

1. Using rate of separation rate and the formula time = distance÷time
2. By using chart and algebra

Let's look at both ways.

1.  Their rate of separation is 40+50 = 90 mph, so time = distance÷time
= 900÷30 = 3 hours.  That's the easy way but your teacher may
not accept it since it doesn't use an equation, but just basic math.

2.  Make this chart:


                  distance     rate    time
Eastbound truck   
Westbound truck     



Both trucks travel the same length of time, so
let that time be t.

Fill that in for the times for both trucks:

                  distance     rate    time
Eastbound truck                          t
Westbound truck                          t



Fill in the two speeds

                  distance     rate    time
Eastbound truck                 40       t
Westbound truck                 50       t



Us distance = rate×time to fill in the distances

                  distance     rate    time
Eastbound truck     40t         40       t
Westbound truck     50t         50       t



The total of their distances is to be 300 miles, so we form the
equation this way:

Eastbound truck's distance + Westbound truck's distance = 300

                     40t + 50t = 300
                           90t = 300
                             t = 
                             t =  hours.

Edwin