Speed, Time and Distance
 The time taken by a train 160 m long, running at 72 km/hr, in crossing an electric pole is

 8 seconds
 9 seconds
 6 seconds
 4 seconds

View Hint View Answer Discuss in Forum
Distance covered in crossing a pole = Length of train
Speed of train = 72 kmph= 72 × 5 m./sec. 18
= 20 m./sec.∴ Required time = 160 20
= 8 secondsCorrect Option: A
Distance covered in crossing a pole = Length of train
Speed of train = 72 kmph= 72 × 5 m./sec. 18
= 20 m./sec.∴ Required time = 160 20
= 8 seconds
 A train 150m long passes a km stone in 30 seconds and another train of the same length travelling in opposite direction in 10 seconds. The speed ot the second train is :

 90 km/hr
 125 km/hr
 25 km/hr
 75 km/hr

View Hint View Answer Discuss in Forum
∴ Speed of train = 150 = 5 m/sec. 30
Speed of train B = x m/sec.
Relative speed = (5+x) m/sec.
∴ Length of both trains = Relative speed × Time
⇒ 300 = (5 + x) × 10⇒ 5 + x = 300 = 30 10
⇒ x = 30 – 5 = 25 m/sec.= 25 × 18 kmph. 5
= 90 kmph.Correct Option: A
∴ Speed of train = 150 = 5 m/sec. 30
Speed of train B = x m/sec.
Relative speed = (5+x) m/sec.
∴ Length of both trains = Relative speed × Time
⇒ 300 = (5 + x) × 10⇒ 5 + x = 300 = 30 10
⇒ x = 30 – 5 = 25 m/sec.= 25 × 18 kmph. 5
= 90 kmph.
 A train is 250m long. If the train takes 50 seconds to cross a tree by the railway line, then the speed of the train in km/hr is :

 10
 9
 5
 18

View Hint View Answer Discuss in Forum
Speed of train = Length of train Time taken in crossing = 250 = 5 m/sec. 50 = 5 × 18 kmph. 5
= 18 kmphCorrect Option: D
Speed of train = Length of train Time taken in crossing = 250 = 5 m/sec. 50 = 5 × 18 kmph. 5
= 18 kmph
 A train passes an electrical pole in 20 seconds and passes a platform 250 m long in 45 seconds. Find the length of the train.

 400m
 200m
 300m
 250m

View Hint View Answer Discuss in Forum
If the length of train be x metre,
then speed of train= x = x + 250 20 45 ⇒ x = x + 250 4 9
⇒ 9x = 4x + 1000
⇒ 9x – 4x = 1000
⇒ 5x = 1000⇒ x = 1000 = 200 metre 5 Correct Option: B
If the length of train be x metre,
then speed of train= x = x + 250 20 45 ⇒ x = x + 250 4 9
⇒ 9x = 4x + 1000
⇒ 9x – 4x = 1000
⇒ 5x = 1000⇒ x = 1000 = 200 metre 5
 If a man walks at the rate of 5 km/hour, he misses a train by 7 minutes. However if he walks at the rate of 6 km/hour, he reaches the station 5 minutes before the arrival of the train. The distance covered by him to reach the station is

 6 km
 7 km
 6.25 km
 4 km

View Hint View Answer Discuss in Forum
Let the required distance be x km.
Difference of time = 7 + 5 = 12minutes = 1 hour 5 Time = Distance Speed
According to the question,x − x = 1 5 6 5 ⇒ 6x − 5x = 1 30 5 ⇒ x = 1 30 5 ⇒ x = 30 = 6 km. 5 Correct Option: D
Let the required distance be x km.
Difference of time = 7 + 5 = 12minutes = 1 hour 5 Time = Distance Speed
According to the question,x − x = 1 5 6 5 ⇒ 6x − 5x = 1 30 5 ⇒ x = 1 30 5 ⇒ x = 30 = 6 km. 5