Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 11)
11.
A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?
Answer: Option
Explanation:
Relative speed = (120 + 80) km/hr
| = |  |
200 x | 5 |  m/sec |
| 18 |
| = | |
500 | m/sec. |
| 9 |
Let the length of the other train be x metres.
| Then, | x + 270 | = | 500 |
| 9 | 9 |
x + 270 = 500
x = 230.
Discussion:
66 comments Page 2 of 7.
Ramya said:
7 years ago
On cross multiplication we get,
9 (500) =4500.
Then, 9 (270+x), 9 goes to another side.
270+x=4500/9,
270+x=500,
X=500-270.
Finally, we get 230.
9 (500) =4500.
Then, 9 (270+x), 9 goes to another side.
270+x=4500/9,
270+x=500,
X=500-270.
Finally, we get 230.
(2)
Pari said:
7 years ago
If we want to find kmph means 15/8.
mph means 8/15 simple formula.
mph means 8/15 simple formula.
Bablu said:
7 years ago
What will happen if both trains are in the same direction as we relative velocity we can subtract but how the equation will come?
Please tell me.
Please tell me.
Reeha said:
7 years ago
Relative speed is to be found when two moving objects or trains are given.
Nilkant said:
7 years ago
Please, tell me when to find relative speed?
Sarang said:
7 years ago
Distance =speed *time,
D=120+80km/h*9,
D=200*5/18*9,
D=1000/2,
D=500-270=230m.
D=120+80km/h*9,
D=200*5/18*9,
D=1000/2,
D=500-270=230m.
(1)
Umar bodha said:
8 years ago
Trains running in opp directions.
Relative speed 120+80 =200.
By converting into m/s,
200*5÷18 =500/,
We know by formula
L=s*t.
Let x be the length of another train
Therefore
X+270=500÷9*9.
X=500-270= 230.
So, x=230m.
Relative speed 120+80 =200.
By converting into m/s,
200*5÷18 =500/,
We know by formula
L=s*t.
Let x be the length of another train
Therefore
X+270=500÷9*9.
X=500-270= 230.
So, x=230m.
Gaurav said:
8 years ago
Relative speed is 120 +80 =200.
Now l =s*t =200*5/18*9=500,
Now, the total dist minus 500-270=230m.
Now l =s*t =200*5/18*9=500,
Now, the total dist minus 500-270=230m.
Sathish said:
8 years ago
Another train's speed and time is already given from that we can calculate the trains length easily why we go for oppostie train?
Murugan said:
8 years ago
@Sam.
Use this formula distance/time = speed.
Use this formula distance/time = speed.
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