Question 207501
Trains A and B are traveling in the same direction on parallel tracks. Train A is traveling at 100mph. train B is traveling at 125mph. Train A passes a station at 4:20 p.m. If train B passes the same station at 4:32 p.m., what time will train B catch up to train A?
:
from the given information, we know that train B is 12 min (.2 hr) behind
 train A, when train A passes the station
:
The distance between the trains at this time: .2 * 125 = 25 mi
:
Let t = time required for train B to catch train A
:
write a distance equation: Dist = speed * time
:
Train B travel dist = Train A travel dist + 25 mi
125t = 100t + 25 
125t - 100t = 25
25t = {{{25/25}}}
t = 1 hr 
:
4:20 + 1:00 = 5:20 pm, B catches A
:
:
Check solution by finding the distances (train B travels 25 mi more than train A)
125 * 1 = 125 mi
100 * 1 = 100 mi
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difference = 25 mi