Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 2)
2.
A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:
Answer: Option
Explanation:
| Speed of the train relative to man = |  |
125 |  m/sec |
| 10 |
| = | |
25 | m/sec. |
| 2 |
| = | |
25 | x | 18 | km/hr |
| 2 | 5 |
= 45 km/hr.
Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
x - 5 = 45 
x = 50 km/hr.
Discussion:
487 comments Page 25 of 49.
Nitesh Nandwana said:
2 decades ago
Hai Rahul, well explanation about relative speed and same and opposite directions. Good job keep it up.
Shobi said:
1 decade ago
Hi friends,
I ave confuesion in relative speed. Can I have some more explanation about relative speed?
I ave confuesion in relative speed. Can I have some more explanation about relative speed?
GwenBiz said:
1 decade ago
@Jothi,
x-5 = 45.
We add 5 to both sides so that we stay with x.
x-5+5 = 45+5.
Therefore,
So x = 50.
x-5 = 45.
We add 5 to both sides so that we stay with x.
x-5+5 = 45+5.
Therefore,
So x = 50.
Sai said:
1 decade ago
This concept is relative to distance not to time so you cannot take a relation like you have mentioned.
Stark said:
1 decade ago
Correct your equation to 125/v1-(10*5)/(5*18) = 10 you will get.
v1 = 13.88 m/s.
==> v1 = 50 kmph.
v1 = 13.88 m/s.
==> v1 = 50 kmph.
Sonali said:
6 years ago
If only one of the speed is given then how will we consider that which one is to be subtracted or not?
Kannips said:
2 decades ago
speed=distance/time.so speed=125/10.....25/2*18/5=45... the question is same direction=x-5=45 x=50
Anish said:
1 decade ago
Hi Manishkumar,Vijaykumarkuppani,Umesh
U hav cleard the points exactly how itz done.
Thanks a lot...
U hav cleard the points exactly how itz done.
Thanks a lot...
Dinesh kumar said:
5 years ago
The speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
Please explain it, friends.
Please explain it, friends.
Eric said:
1 decade ago
@Shafi.
This method is quite simple and explain the whole concept, thanks for the nice explanation.
This method is quite simple and explain the whole concept, thanks for the nice explanation.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers