word problem help

Question

two bullet trains leave a station at the same time. One train is travelling north at 20 miles faster then one headed south. In 5 hours the two trains will be 2013 miles apart. How fast are they going?

Answer 1

Let x = speed of the southbound train

 

Then, x + 20 = speed of the northbound train

 

Distance = (Rate)(Time)

 

Distance of southbound train in 5 hours = 5x

 

Distance of northbound train in 5 hours = 5(x+20) = 5x + 100

 

5x + (5x + 100) = 2013

 

10x + 100 = 2013

 

          10x = 1913

 

             x = 191.3 mph

 

The southbound train is travelling at 191.3 mph and the northbound train is travelling at 211.3 mph.