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 5 of 6.
Aks said:
7 years ago
4.5 * 8.4 - 5.4 * 8.5 = 45.9 - 37.8 = 8.1.
(6)
San said:
8 years ago
How distance and speed are equal here?
Deepika said:
1 decade ago
Please explain me only the last step.
Swetha said:
1 decade ago
Good explanation. Thank you manasa.
Divya said:
1 decade ago
Thank you manasa. Nice explanation.
Pooja said:
8 years ago
Nice explanation, Thanks @Sathees.
Mpa said:
8 years ago
How does distance can be equal?
Maggi said:
9 years ago
How 2.25 came? Please tell me.
Rrrr said:
4 years ago
The answer should be 80.
Yakesh said:
1 decade ago
Thank you! gowthami.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers