Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 28)
28.
A train overtakes two persons walking along a railway track. The first one walks at 4.5 km/hr. The other one walks at 5.4 km/hr. The train needs 8.4 and 8.5 seconds respectively to overtake them. What is the speed of the train if both the persons are walking in the same direction as the train?
Answer: Option
Explanation:
| 4.5 km/hr = |  |
4.5 x | 5 |  |
m/sec = | 5 | m/sec = 1.25 m/sec, and |
| 18 | 4 |
| 5.4 km/hr = | |
5.4 x | 5 | |
m/sec = | 3 | m/sec = 1.5 m/sec. |
| 18 | 2 |
Let the speed of the train be x m/sec.
Then, (x - 1.25) x 8.4 = (x - 1.5) x 8.5
8.4x - 10.5 = 8.5x - 12.75
0.1x = 2.25
x = 22.5
 Speed of the train = |
|
22.5 x | 18 | |
km/hr = 81 km/hr. |
| 5 |
Discussion:
54 comments Page 4 of 6.
Yubaraj said:
10 years ago
If trains are in same direction the speed should be subtracted otherwise add.
Siva said:
1 decade ago
If the question is to find the length of the train, then how to solve it?
BALIRAM said:
1 decade ago
When add the speed and when subtract the speed in the case two train.
Jayasree said:
9 years ago
Can anyone explain the first step?
= 4.5 km/hr = 4.5*5/18.
= 4.5 km/hr = 4.5*5/18.
Anjaneyuluraju said:
5 years ago
Do the sum the same as 27th sum and get the answer.
Priyanka said:
8 years ago
Why equating both distances?
Please explain me.
Please explain me.
Chanda said:
1 decade ago
Please some one explain me in detail. Thank you
Sanjeev said:
7 years ago
Can't understand. Please explain me in detail.
Vinay rawat said:
1 decade ago
How can we assume that the distance is equal ?
Rahul said:
7 years ago
Thanks for explaining the solution @Swapnil.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers