Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 8)
8.
A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Answer: Option
Explanation:
| Formula for converting from km/hr to m/s: X km/hr = |  |
X x | 5 |  |
m/s. |
| 18 |
| Therefore, Speed = | |
45 x | 5 | m/sec |
= | 25 | m/sec. |
| 18 | 2 |
Total distance to be covered = (360 + 140) m = 500 m.
| Formula for finding Time = | |
Distance | |
| Speed |
 Required time = |
|
500 x 2 | sec |
= 40 sec. |
| 25 |
Discussion:
78 comments Page 8 of 8.
Divya said:
2 decades ago
How can we get 5/18 ?
Rahul kulkarni said:
2 decades ago
Do not go for complication.
Convert 45km to m i.e. 45000m & 1hr=3600sec.
Then, 45000/3600sec. therefore 12.5m/sec. Total distance to be covered is
360m + 140m = 500m
Then, time required to pass the bridge is 500m/12.5m/s = 40sec.
Convert 45km to m i.e. 45000m & 1hr=3600sec.
Then, 45000/3600sec. therefore 12.5m/sec. Total distance to be covered is
360m + 140m = 500m
Then, time required to pass the bridge is 500m/12.5m/s = 40sec.
Saikiran said:
2 decades ago
45*5/18=25/2. I can't understand.
How you took 9 as a common number on both numerator and dinominator.
How you took 9 as a common number on both numerator and dinominator.
Rajivgandhi said:
2 decades ago
45 x 5/18 means (45 x 5)/18=225/18.
Then,
Divide by 9 both the Numerator and Dinominator.
Sure, u got Ans=25/2
Then,
Divide by 9 both the Numerator and Dinominator.
Sure, u got Ans=25/2
Rajivgandhi said:
2 decades ago
45x5/18 means (45x5)/18=225/18(divide by 9 both the numerator and dinominator).Then you will get the answer 25/2.
PrinceDarwin said:
2 decades ago
45 x 5/18 m/sec = 25/2 m/sec. I CANTT UNDERSTAND THE LOGIC. Plese explain
Sundar said:
2 decades ago
Hi Naveen,
Time = Distance / Speed
Here,
Distance = 500 m.
Speed = 25/2
Therefore, Time = 500/ (25/2)
Time = 500/12.5 = 40 sec.
or
Time = 500 x 2 / 25 = 40 sec.
Time = Distance / Speed
Here,
Distance = 500 m.
Speed = 25/2
Therefore, Time = 500/ (25/2)
Time = 500/12.5 = 40 sec.
or
Time = 500 x 2 / 25 = 40 sec.
(1)
Naveenreddy said:
2 decades ago
It ok 500 m but how come (500x2)/25 explain please.
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