Question

A train leaves Philadelphia at 5:00 PM. A second train leaves the same city in the same direction at 7:00 PM. The second train travels 30mph faster than the first. If the second train overtakes the first at 11:00 PM, what is the speed of each of the two trains?

Answer 1

Details of first train :

Time taken = 7 hrs; speed = x mph; distance = 7x miles

Details of second train :

Time taken = 4 hrs; speed = x+30 mph; distance = 4x + 120 miles

read. equation;

4x+120 = 7x

or, 3x = 120

or, x = 40 mph (speed of first train)

x+30 mph = 70 mph (speed of second train)