Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 13)
13.
Two trains, each 100 m long, moving in opposite directions, cross each other in 8 seconds. If one is moving twice as fast the other, then the speed of the faster train is:
Answer: Option
Explanation:
Let the speed of the slower train be x m/sec.
Then, speed of the faster train = 2x m/sec.
Relative speed = (x + 2x) m/sec = 3x m/sec.
 |
(100 + 100) | = 3x |
| 8 |
24x = 200
| x = |
25 | . |
| 3 |
| So, speed of the faster train = | 50 | m/sec |
| 3 |
| = |  |
50 | x | 18 |  km/hr |
| 3 | 5 |
= 60 km/hr.
Discussion:
74 comments Page 4 of 8.
Reeha said:
7 years ago
@Eudis.
It's the basic conversion principle, From km/hr to m/s we can use 5/18 and the reciprocal for vice versa.
It's the basic conversion principle, From km/hr to m/s we can use 5/18 and the reciprocal for vice versa.
Vaasudevarao said:
1 decade ago
Speed= d/t (100+100)=200*18/5=90km/h two train speed x+2x =3x 3x=90; x=90/3 x=30 so faster train speed is 2x =60
Jyoti said:
1 decade ago
Dear ravi this is speed of first train +speed of second train=relative speed of both trains moving opposite.
Thenmolzhi said:
1 decade ago
Relative speed = (x+y);
x = x;
y = Twice faster than 'x', So 2x;
y = 2x;
Relative speed = (x+2x) = 3x.
x = x;
y = Twice faster than 'x', So 2x;
y = 2x;
Relative speed = (x+2x) = 3x.
Navin said:
9 years ago
x = 25/3
So, speed of the faster train = 50/3 m/sec.
I can't understand these steps please help me.
So, speed of the faster train = 50/3 m/sec.
I can't understand these steps please help me.
Garvit said:
8 years ago
Why wasn't the speed of one train 1 considered x and other considered y? Why we're both taken as x?
Ganesh said:
7 years ago
Consider one train x speed and another one is x one twice speed to the other train then x+2x-3x.
Qweg said:
9 years ago
In this, we are not considering the distance that is between them? Should it be considered too?
Abhinav said:
1 decade ago
When the train is Opposite direction, than the relative speed is add to both (100+100)= 200
Seema said:
1 decade ago
If these two trains are moving in opposite direction then how can we add their distance.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers