Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 20)
20.
A train moves past a telegraph post and a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?
Answer: Option
Explanation:
Let the length of the train be x metres and its speed by y m/sec.
| Then, | x | = 8  x = 8y |
| y |
| Now, | x + 264 | = y |
| 20 |
8y + 264 = 20y
y = 22.
 Speed = 22 m/sec = |
 |
22 x | 18 |  |
km/hr = 79.2 km/hr. |
| 5 |
Discussion:
46 comments Page 4 of 5.
Rana sk said:
8 years ago
20-8=12,
264÷12=22
22*18÷5=79.2.
264÷12=22
22*18÷5=79.2.
Ginil kumar said:
7 years ago
@Rana Sk.
This is the simple way to get this answer. Thanks for explaining.
This is the simple way to get this answer. Thanks for explaining.
Guravareddy namburi said:
7 years ago
S=D/T.
GIVEN DATA IS D=264, T1=8, T2=20.
LET TRAIN DISTANCE IS X,& TRAIN SPEED IS Y.
SO,
Y=X/8.
X=8Y.
THEN RELATIVE SPEED = X+264/20.
here speed is Y.
Y=X+264/20.
we know X value.
Y=(8Y+264)/20,
20Y=8Y+264,
12Y=264,
Y=264/12= 22 m/s.
Now its convert into km/h.
22*18/5=396/5=79.2 km/h.
GIVEN DATA IS D=264, T1=8, T2=20.
LET TRAIN DISTANCE IS X,& TRAIN SPEED IS Y.
SO,
Y=X/8.
X=8Y.
THEN RELATIVE SPEED = X+264/20.
here speed is Y.
Y=X+264/20.
we know X value.
Y=(8Y+264)/20,
20Y=8Y+264,
12Y=264,
Y=264/12= 22 m/s.
Now its convert into km/h.
22*18/5=396/5=79.2 km/h.
Diksha rajput said:
7 years ago
It can be done directly.
D=264m T= (20-8) =12 s.
S=D/T =264/12 =22.
Converting it into kmph.
22*18/5=79.2.
D=264m T= (20-8) =12 s.
S=D/T =264/12 =22.
Converting it into kmph.
22*18/5=79.2.
Sainpal said:
7 years ago
Nice method. Thanks @Diksha Rajput.
Akhila said:
7 years ago
Please explain this.
After finding the relative speed 20-8=12secs, why we are not taking the total distance as x+264?
After finding the relative speed 20-8=12secs, why we are not taking the total distance as x+264?
Aishuy said:
7 years ago
How will make 22*18/5? Please explain this step.
Shambhu said:
7 years ago
Hi, I can't understand please explain me.
Laxman biradar said:
7 years ago
Nice explanation @Gaurav Reddy.
Prashant said:
6 years ago
Thanks @Randhir.
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