A train traveled 400 miles in 9 hours. The speed of the train for the first part of the journey was 40 miles per hour while the speed for the second part of the journey was 50 miles per hour.

Question

Find the distance traveled when the train was traveling at 50 per hour.

Answer 1

answer: 200 miles traveled for 4 hours at speed 50 mph

distance = speed times time

d=st miles = mph x hours = miles/hour x hours

t= time for train at 40 mph 9-t= time for train at 50mph

d = d1 + d2

= s1t + s2t

= 40t +50(9-t)

400 = 40t + 450 -50t

10t = 50

t =50/10 =5 hours at 40 mph

that's 5 x 40 = 200 miles at 40 mph, with 400-200= 200 miles at 50 mph

t = 5 hours, 9-5 = 4 hours at 50 mph

4 hours at 50 mph = 4x50 = 200 miles

5 x 40 mph + 4 x 50 mph = 200 + 200 = 400 miles

Answer 2

distance = speed times time

d=st

400=40t + 50(9-t)

400=40t+450-50t

10t = 50

t=5 hours at 40 mph

The train traveled 9-5= 4 hours at 50mph covering 4x50=200 miles

The train traveled the first 200 miles in 5 hours at 40mph

and the 2nd 200 miles in 4 hours at 50mph