Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 17)
17.
A train 800 metres long is running at a speed of 78 km/hr. If it crosses a tunnel in 1 minute, then the length of the tunnel (in meters) is:
Answer: Option
Explanation:
| Speed = |  |
78 x | 5 |  |
m/sec | = | |
65 | |
m/sec. |
| 18 | 3 |
Time = 1 minute = 60 seconds.
Let the length of the tunnel be x metres.
| Then, | |
800 + x | |
= | 65 |
| 60 | 3 |
3(800 + x) = 3900
x = 500.
Discussion:
52 comments Page 4 of 6.
Agggy said:
3 months ago
Why we are adding the length of train and length of tunnel? Anyone please explain to me.
Smith said:
1 decade ago
Train speed 7800m/60m = 1300m.
Length of tunnel is 1300-800 = 500.
Its very simple.
Length of tunnel is 1300-800 = 500.
Its very simple.
Pradnyashree said:
1 decade ago
If we do 3(800+x)= 60*65,
3*800+3x=3900,
2400+3x=3900
3x=3900-2400
3x=500
x=166.66
3*800+3x=3900,
2400+3x=3900
3x=3900-2400
3x=500
x=166.66
Joel said:
3 years ago
@Pradnyashree.
How is 3900-2400 =500?
It's 1500. Can anyone explain that?
How is 3900-2400 =500?
It's 1500. Can anyone explain that?
(2)
Arushi said:
6 years ago
I am not getting, how come 5/18? Please, someone explain me.
Sasinrit said:
7 years ago
Speed =78000/3600=1300/min.
Length of tunnel=1300-800=500.
Length of tunnel=1300-800=500.
(1)
Subham baksi said:
1 decade ago
Why (800+x) /60? Why divided 60 is not coming in my mind?
Dinesh said:
9 years ago
If there will be 75 km/h then what will be the answer?
Kannika said:
1 decade ago
Why we are adding train length to the tunnel length?
Asmamaw said:
8 years ago
How the number 5/18 came? please clarify me.
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