Problema Solution
A train leaves Taipei for a nearby city at 3:45 pm, averaging 80 mph. Another train leaves the mearby city for Taipei at 7:00 pm averaging 100pmh. If the nearby city is 440 miesl from Taipei, to the nearest minute, at what time will the trains pass each other?
Answer provided by our tutors
let
t = the time of the travel from Taipei to the nearby city
the difference in time between 3:45 pm and 8:00 pm is 4 hour and 15 min = 4 15/60 = 4.25 hours
t - 4.25 = = the time of the travel from the nearby city to Taipei
v1 = 80 mph the speed of the train from Taipei to the nearby city
v2 = 100 mph the speed of the train from the nearby city to Taipei
d = 440 miles the distance between the nearby city and Taipei
v1*t + v2(t - 4.25) = 440
80t + 100(t - 4.25) = 440
by solving the equation we find
t = 173/36 hours = 4 hours 29*60/36 min = 4 hours 47 minutes
click here to see the step by step solution of the equation
4 hours 47 minutes after 3:45 pm is 8:32 pm
the trains will pass each other at 8:32 pm.