Ratio of length of two trains is 2 : 3. Coming from opposite direction, they cross a pole in 5 seconds each . Then in what time will they cross each other .
Answer & explanation
Correct answer: option 2
Ratio of train 1 : train 2
Distance 2 : 3
Speed 2 : 3 ( distance = speed × time , so ratio of distance and speed is same .)
As both train cross a man in 5 sec . So length of train1
Distance = Speed × Time
Length of train 1 = 2R × 5 = 10R
Similarly, legth of train 2 = 3R × 5R = 15R
Total distance = 25R meter
As trains moves in opposite direction . so relative speed = ( 2 + 3 )R = 5R m/sec
Time taken by trains to cross each other = \(\frac{25R}{5R}\) = 5 sec .