Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 10)
10.
A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
Answer: Option
Explanation:
Speed of train relative to jogger = (45 - 9) km/hr = 36 km/hr.
| = |  |
36 x | 5 |  m/sec |
| 18 |
= 10 m/sec.
Distance to be covered = (240 + 120) m = 360 m.
 Time taken = |
|
360 | sec |
= 36 sec. |
| 10 |
Discussion:
106 comments Page 7 of 11.
Raji said:
1 decade ago
What is the difference between 2nd problem and 10th problem?
Ankush said:
1 decade ago
5/18 we can get like that.
Suppose speed is 10 km/hr so we can say like that.
(10)*1000/3600 m/second, so 1000/3600 will become 5/18.
Suppose speed is 10 km/hr so we can say like that.
(10)*1000/3600 m/second, so 1000/3600 will become 5/18.
Sushanto said:
1 decade ago
Why (36 x 5/18) is used? How you get 5/18?
Monica said:
1 decade ago
Why we add track length means because man is running on track? So man gets the track length.
Padma said:
1 decade ago
Question asked about at what time train cross man. Man has no length then why we add track length?
Ram said:
1 decade ago
Answer is 48 sec as jogger also jogs 2.5x distance.
= 360+2.5x/x = 10.
= 360+2.5x = 10x.
= 360 = 7.5x.
= 48 = x.
Hence 48 sec is the answer.
= 360+2.5x/x = 10.
= 360+2.5x = 10x.
= 360 = 7.5x.
= 48 = x.
Hence 48 sec is the answer.
Prashant said:
1 decade ago
Please clear my doubt.
Let the train pass after t time.
So train has to cover (120+240+x)/45 in t time.
And jogger covers x/9 in t time.
(120+240+x) /45 = x/9.
Answer is 90 sec but logic is correct that they both meet after t time.
Let the train pass after t time.
So train has to cover (120+240+x)/45 in t time.
And jogger covers x/9 in t time.
(120+240+x) /45 = x/9.
Answer is 90 sec but logic is correct that they both meet after t time.
Atoria M. Horace said:
1 decade ago
I still can't understand how the 5/18 came about.
Ramsha said:
1 decade ago
Yes @Vedant, I also get the same answer through the same process.
Vedant said:
1 decade ago
@People considering distance traveled by jogger.
240 + 120 + 9*A (5/18) / (45*5/18) = A.
This will give A=36 so given solution is correct do no take relative speed concept just simply add distance to be covered and divide by train speed.
240 + 120 + 9*A (5/18) / (45*5/18) = A.
This will give A=36 so given solution is correct do no take relative speed concept just simply add distance to be covered and divide by train speed.
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