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 4 of 10.
Ankita said:
9 years ago
Distance between two stations A and B is 100 km, two trains with speed 60 km/h and 40 km/h are running towards each other. What is the distance from station A where both trains will meet?
Can anyone find the answer?
Can anyone find the answer?
Ayush said:
9 years ago
60 km as relative speed of both the trains is 100 km/hr and
distance = 100km.
Then time taken to meet = distance/speed(relative).
T = 100/100 = 1 hr
So the trains will meet each other after 1 hour so,
Distance covered by first train in 1 hour = 60km/hr * 1hr = 60 km,
Distance covered by second train in 1 hour = 40km/hr * 1hr = 40 km,
Therefore, the distance from station A where both trains will meet = 60km.
distance = 100km.
Then time taken to meet = distance/speed(relative).
T = 100/100 = 1 hr
So the trains will meet each other after 1 hour so,
Distance covered by first train in 1 hour = 60km/hr * 1hr = 60 km,
Distance covered by second train in 1 hour = 40km/hr * 1hr = 40 km,
Therefore, the distance from station A where both trains will meet = 60km.
Sonic said:
9 years ago
Why it's taken x-1 but not x+1 because train 2 starts 1 hr later?
Dezosa said:
6 years ago
The speed of one train is twice the other so let,
Speed of 1st train is Y.
Speed of 2nd train is 2Y.
Then distance between point A and B is 6Y.
Suppose they meet x hours after 5 a.m.
Distance covered by 1st train in X hours = YX km.
Distance covered by B in (X - 2) hours = 2Y(X - 2) km.
Therefore YX + 2Y(X - 2) = 6Y.
=> YX + 2YX - 4Y = 6Y.
=> 3YX = 10Y.
=> X =10/3 (in hours).
=> X =10/3*60 (because converting into minutes).
=> X =200 minutes.
200 minutes means 3 hour 20 minutes.
So, They meet at 8 : 20 p.m.
Speed of 1st train is Y.
Speed of 2nd train is 2Y.
Then distance between point A and B is 6Y.
Suppose they meet x hours after 5 a.m.
Distance covered by 1st train in X hours = YX km.
Distance covered by B in (X - 2) hours = 2Y(X - 2) km.
Therefore YX + 2Y(X - 2) = 6Y.
=> YX + 2YX - 4Y = 6Y.
=> 3YX = 10Y.
=> X =10/3 (in hours).
=> X =10/3*60 (because converting into minutes).
=> X =200 minutes.
200 minutes means 3 hour 20 minutes.
So, They meet at 8 : 20 p.m.
Bhat ashraf said:
9 years ago
The difference of speeds of two trains P & Q is 20km/hr. Train P & Q start from points A & B & move towards each other. If the trains meet each other after 2 hr of the journey. What is the speed of the faster train?
Please answer it.
Please answer it.
Swasti said:
9 years ago
How this 3 hr comes?
Mary said:
9 years ago
How to solve if they move in the same direction?
Basharat said:
9 years ago
This is based on relative speed.
If they are in opposite directions just add their speeds if they are in same directions subtract their speeds.
If they are in opposite directions just add their speeds if they are in same directions subtract their speeds.
Sachin said:
9 years ago
Here
V1 =20 km/hr.
V2 = 25km/hr.
Time of meet they
= 110-20/20 + 25.
= 2hr.
Then 8+2 = 10am.
V1 =20 km/hr.
V2 = 25km/hr.
Time of meet they
= 110-20/20 + 25.
= 2hr.
Then 8+2 = 10am.
Chittaranjan said:
8 years ago
A_________________110KM______________________B.
7.00 AM. 8.00 AM.
20 KMH. 25 KMh.
2nd train after 1 hour.
So 1st train gone to 20 km.
Because totally 110-20 = 90 km.
Now 20 kmh+25 kmh = 45 kmh.
90/45 = 2 hours.
Now we count 8.00 am+ 2 hours = 10.00 AM.
7.00 AM. 8.00 AM.
20 KMH. 25 KMh.
2nd train after 1 hour.
So 1st train gone to 20 km.
Because totally 110-20 = 90 km.
Now 20 kmh+25 kmh = 45 kmh.
90/45 = 2 hours.
Now we count 8.00 am+ 2 hours = 10.00 AM.
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