Question

A freight train leaves a station and travels north at 60 mph. 4 hours ​later, a passenger train leaves on a parallel track and travels north at 100 mph. How long will it take the passenger train to overtake the freight​ train? How far from the station will they​ meet?

Answer 1

Answer:

first do:

60mph * 4 hours= 240mi

Let D = the distance the passenger train has to  

travel to catch the freight train

Start a stopwatch when the passenger train leaves

Let t = the time on the stopwatch when they meet

Equation for freight train:

d-240=60t

Equation for passenger train:

d=100t

all together:

100t-240=60t

we can do 100t-60t because they both have (t)= 40t

40t=240 *now divide 240 by 40= 6

THEN do:

D= 100mph x 6= 600mi

They will meet 600 mi from the station

to check:

d-240=60t x 6

600-240= 360

60 x 6= 360

360=360