220 meter long train is running with a speed of 59 km/hr. In what time will it pass a man who is running at 7 km/hr in the direction opposite to that in which the train is going?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 12 second
When the train and the man move in opposite directions, they close the gap at the sum of their speeds. To pass the man, the train covers its own length at this relative speed; the speed is changed from km/hr to m/s (multiplying by \(\frac{5}{18}\)) to match the length in metres.
Relative speed: \(59+7=66\) km/hr \(\displaystyle=66\times\frac{5}{18}=\frac{55}{3}\) m/s
Time to cover the train’s length of 220 m: \(\displaystyle220\div\frac{55}{3}=\frac{220\times3}{55}=\) 12 seconds