Question

Wind is blowing from west to east along two parallel tracks. A train is moving on each track in opposite directions. They have same speed when no wind is blowing. Now, one train has speed double that of the other. The speed of each train is

• A. Equal to that of wind
• B. Double that of wind
• C. Three times that of wind
• D. Half of that of wind

Answer 1

The correct option is C Three times that of wind

Let the speed of train be x and speed of wind be y.
On the track where train and wind are in same direction net speed is x+y.
On the track where train and wind are in opposite direction net speed is x-y.
Now , as per question,
$x+y=2(x-y)\Rightarrow x=3y$