Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 30)
30.
Two stations A and B are 110 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?
Answer: Option
Explanation:
Suppose they meet x hours after 7 a.m.
Distance covered by A in x hours = 20x km.
Distance covered by B in (x - 1) hours = 25(x - 1) km.
20x + 25(x - 1) = 110
45x = 135
x = 3.
So, they meet at 10 a.m.
Discussion:
92 comments Page 3 of 10.
Knn said:
1 decade ago
Yuvraj. Cool answer!
Damodar Narayan said:
1 decade ago
A----------110---------B 7am
A---------90--------B 8am(Speed of the 1st train is 20 km/h)
A----45----B 9am(relative speed=20+25(45) km/h)
AB 10am
A---------90--------B 8am(Speed of the 1st train is 20 km/h)
A----45----B 9am(relative speed=20+25(45) km/h)
AB 10am
Sandy said:
1 decade ago
Thanks yuvraj.
Ajay said:
1 decade ago
Its Simple in another way that Total Distance was 110KM.... A start at 7 AM at the speed of 20 KM in 3 Hrs he will cover 60KMS whereas B start at 8 AM @ speed of 25 KM/Per Hour in 2 HRS he will covered 50 KMS that means 7+3=10AM
Arun said:
1 decade ago
Why we use x-1 not x+1?
Amit Kumar said:
1 decade ago
Dear Arun,
Because train is started 1 hours late, thats why x-1
Because train is started 1 hours late, thats why x-1
Joicy said:
1 decade ago
Why (X-1) term is used?
Charles @ Redhills said:
1 decade ago
@Joicy.
The train B starts an hour later than the train A. Thus the train time A is assumed as x (started at 7 am) and the train B starts at time 8 am which is later an hour of time x hence its x-1. Hope its clear to you now.
The train B starts an hour later than the train A. Thus the train time A is assumed as x (started at 7 am) and the train B starts at time 8 am which is later an hour of time x hence its x-1. Hope its clear to you now.
Bhoopesh Choudhary said:
1 decade ago
The answer of this question is incorrect if the B train start at 8am and by the speed 25km\hr then it will cover the distance of 50km in next 2 hours but the train A will cove the distance of 60km in next 3 hour by the peed of 20km\hr.
So both can be meet at 10 a.m.
So both can be meet at 10 a.m.
Manish Dabhi said:
1 decade ago
Train A Travel in 1 hour 20 km at 7 am.
They both started together 8 am.
That's why 110-20 = 90km Remaining,
Relative Speed = (20+25) = 45 km/hr.
Time = (Distance/Speed).
= (90/45)
= 2 Hours
That's why 8am + 2 hours = 10 am.
They both started together 8 am.
That's why 110-20 = 90km Remaining,
Relative Speed = (20+25) = 45 km/hr.
Time = (Distance/Speed).
= (90/45)
= 2 Hours
That's why 8am + 2 hours = 10 am.
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