Melissa Brinkley: Train A and Train B math problem?
Train A and B are traveliong in the same direction on parallel tracks. Track A is traveling at 40 mph B is going 48 mph. If train A passes the station at 525pm and train b passes the same station at 540 what time will train B catch up to train A?
Answers and Views:
Answer by como
Train A________Train B
40 mph________48 mph
5 : 25__________5 : 40
In 15 mins train A travels 10 miles
Relative speed of trains is 8 mph
Time for train B to travel 10 miles is given by :-
10/8h = 5/4h = 1h 15min
I’m going to let h be the number of hours it takes train B to catch up to train A.
so when train B passes the station, train A has already been traveling 15 minutes (1/4 hour)
distance train A has traveled = (h+1/4)hours * 40 miles per hour = (40h + 10) miles
distance train B has traveled = h hours * 48 miles per hour = (48h) miles
these distances are the same (otherwise train B won’t have “caught up”), so
40h + 10 = 48h
solve for h
10 = 8h <– subtract 40h from both sides
5/4 = h <– divide both sides by 8 and reduce
so the time it takes train B to catch up is 1 hour, 15 minutes.
So…. add 1 hour 15 minutes to the time train B passed the station and it will be
6:55pm
Answer by shazam!t=5:40 – 5:25
t = 15″
r = 48mph-40mph
r = 8 mph
8mph = 480″
480″/15″ = 32″
32″ + 5:25 = 5:57
Leave a Reply