distance rate time

Question

A train leaves Chicago at 1:00 PM. A second train leaves the same city in the same direction at 9:00 PM. The second train travels 240mph240⁢mph 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

Hi Rachelle,

 

let r = the speed of the first train that leaves at 1 pm

 

r + 240 = the speed of the second train that leaves at 9 pm

 

At 11 pm when they meet, they have traveled the same distance from the starting point

 

distance = speed · time

 

(r)(10 hours) = (r + 240)(2 hours)

 

10r = 2r + 480

 

8r = 480

 

r = 60

 

The first train's speed is 60 mph

 

The second train's speed is 300 mph