Question 526667
Freight Train.
d = r*t
t = 7 hr
r = x mph
.
Passenger Train.
d = r*t
t = 4 hr
r = x+30 mph
.
When the passenger train overtakes the freight train, they will have traveled the same distance, 'd'.
.
d = d
so
7*x = 4*(x+30)
7x = 4x + 120
3x = 120
x = 40 mph = speed of freight train
.
x+30 = 70 = speed of passenger train
.
Do the distance work out?
7 * 40 = 280 miles
4 * 70 = 280 miles
Correct.
.
Done.