Aptitude Questions and Answers
A train 120 meters long is running with a speed of 60 km/hr. In what time will it pass a boy who is running at 6 km/hr in the direction opposite to that in which the train is going?
Speed of train relative to boy= `(60 + 6)` km/hr = 66 km/hr
`= [66 xx 5/18]` m/sec = `[55/3]` m/sec.
Time taken to pass the boy=` [120 xx 3/55]` sec = 6.54 seconds
Find the speed of the train, if a train 142 m long passes a pole in 6 seconds.
Speed = `[142/6]` m/sec
= `[23.6 ** 18/5]` km/hr
= 84.9 km/hr
The driver of a maruti car driving at a speed of 68km/h locates a bus 40m ahead of him. After 10sec the bus is 60m behind. The speed of the bus is
Let the speed of the bus be x m/s
speed of the car = 68km/hr (or) `170/9` m/s
in 10s the car covers a distance of 100m (40m + 60m = 100m) at a speed of (`170/9` – x)m/s
distance = speed*time
`100 = (170/9 -x) **10`
x = `80/9` m/s
Now convert it to km/hr which is 32 km/hr
A train 150 m long is running with a speed of 68 kmph. In what time will it pass a man who is running at 8 kmph in the same direction in which the train is going?
Speed of the train relative to man = (68 - 8) kmph = (60* `5/18`) m/sec = (`50/3`)m/sec
Time taken by the train to cross the man I = Time taken by It to cover 150 m at `50/3` m / sec
= 150 *`3/ 50` sec = 9 sec