Problems on Trains
- 1. Two trains running in opposite directions cross a man standing on the platform 54s and 34s respectively and they cross each other in 46 s . Find the ratio of their speeds.?
Options- A. 3 : 2
- B. 2 : 3
- C. 5 : 3
- D. 3 : 5 Discuss
Correct Answer: 3 : 2
Explanation:
Let the speeds of two trains be x and y, respectively .
? Length of 1st train = 54x
Length of the 2nd train = 34y
According to the question.
(54x + 34y) / (x + y) = 46
? 54x + 34y = 46x + 46y
? 27x + 17y = 23x + 23y
? 4x = 6y
? x/y = 3/2
? x : y = 3 : 2
- 2. Two trains are running 40 km/h and 20 km/h respectively, in the same directions. The fast train completely passes a man sitting in the slow train in 5 s. The length of the fast a train is?
Options- A. 232/9 m
- B. 27 m
- C. 277/9 m
- D. 23 m Discuss
Correct Answer: 277/9 m
Explanation:
The length of the fast train = Relative speed x Time
= (40 - 20) x (5/18) x 5 = 277/9 m
- 3. Two trains of same length take 6 s and 9 s, respectively to cross a pole. If both the trains are running in the same direction, then how long will they take to cross each other?
Options- A. 30 s
- B. 36 s
- C. 40 s
- D. 42 s Discuss
Correct Answer: 36 s
Explanation:
Given that, t1 = 6 s and t2 = 9 s
Then, time taken by the trains to cross each other = 2t1 t2 / (t2 - t1)
= (2 x 6 x 9)/(9 - 6) = 36 s
- 4. P and Q are 27 km away. Two trains will having speeds of 24 km/h and 18 km/h respectively starts simultaneously from P and Q and travel in the same direction. They meet at a point R beyond Q. Distance QR is
Options- A. 126 km
- B. 81 km
- C. 48 km
- D. 36 km Discuss
Correct Answer: 81 km
Explanation:
If the trains meet after t h.
Relative speed of train = (24 -18) = 6 km/h
? Distance = 27
? t = 27/6 = 9/2 h
? QR distance travel by train which is travelling at a speed of 18 km/h = 18t = 18 x 9/2 = 81 km
- 5. Two station P and Q are at a distance of 160 km. Two trains starts moving from P and Q to Q and P respectively and meet each other after 4 h . If speed of the train starting from P is more than that of other train by 6 km/h. then find the speeds of both the trains, respectively.?
Options- A. 19 km/h, 13 km/h
- B. 13 km/h, 9 km/h
- C. 17 km/h, 23 km/h
- D. 16 km/h, 10 km/h Discuss
Correct Answer: 17 km/h, 23 km/h
Explanation:
Let the speed of both trains be V km/h and (V + 6) km/h, respectively
Then, according to the question.
160 = V x 4 + (V + 6) x 4
? 160 = 4V + 4V + 24
? 40 = V + V + 6
? 2V + 6 = 40
? 2V = 34
? V = 17
Hence, speeds of both the trains are 17 km/h and (17 + 6 ) km/h i,e 17 km/h and 23 km/h .
- 6. A train leaves Mumbai for Goa at 3:45 pm and goes at the rate of 50 km/h. Another train leaves Goa for Mumbai at 2:35 pm and distance between Mumbai and Goa is 510 km. at what distance from Mumbai will the two trains meet?
Options- A. 200 km
- B. 150 km
- C. 145 km
- D. 300 km Discuss
Correct Answer: 200 km
Explanation:
Let the two trains meet at D km from Mumbai. Then,
3:45 pm + D/50 = 2 : 35 pm + 510 - D/60
? (3:45 pm - 2:35 pm) + (D/50 + D/ 60) = 510/60
? (11/6 h) + D{( 50 + 60 / 50 x 60)} = 17/2
? D(110/3000) = 17/2 - 7/6
? D(110/3000) = (51 - 7)/6 = 44/6
? D = (44/6) x (3000/110) = 200 km
- 7. Train A crosses a pole in 25 s and train B crosses the pole in 1 min 15 s . Length of train A is half the length of train B. What is the ratio between the speeds of A and B, respectively?
Options- A. 3 : 2
- B. 3 : 4
- C. 4 : 3
- D. Could't be determined Discuss
Correct Answer: 3 : 2
Explanation:
Let the lengths of the trains A and B be a and 2a, respectively.
when a train crosses a pole, it covers the distance equal to its length.
? Required ratio of speeds = a / 25 : 2a /75 = 3 : 2
- 8. A 110 m long train crosses a tree in 3 s. How long will take to cross 165 m long platform and 135 m long bridge, if platform and bridge are at a distance of 30 m?
Options- A. 12 s
- B. 15 s
- C. 16 s
- D. 18 s Discuss
Correct Answer: 12 s
Explanation:
The distance covered by the train to cross the platform and bridge
= Length of the platform + Length of bridge + Distance between platform and bridge + Length of the train
= 165 + 135 + 30 + 110 = 440 m
Speed of train = 110 /3 m/s
? Required time taken = 440/(110/3) = 12 s
- 9. The distance travelled by a train is 1830 km. The speed of the train is one more than twice the time taken to travel the distance. What will be the respective ratio of the speed of the train and time taken to travel?
Options- A. 30 : 61
- B. 61 : 30
- C. 25 : 51
- D. 51 : 25 Discuss
Correct Answer: 61 : 30
Explanation:
Let time taken to cover the distance = t
? Speed = (2t + 1)
? t(2t + 1) = 1830 ? 2t2 + t = 1830
? 2t2 + t - 1830 = 0
? t = -1 ± ?(1)2 - 4 x 2 x(-1830) / 2 x 2
= -1 ± ?1 + 14640 / 4
= -1 ± 121 / 4
Taking '+' sign t = -1 + 121 / 4 = 120/4 = 30
? Required ratio = (2 x 30 + 1) : 30 = 61 : 30
- 10. The average speed of a bus is three-fourth the average speed of a train. The train covers 240 km in 12 h . How much distance will the bus cover in 7 h?
Options- A. 110 km
- B. 115 km
- C. 105 km
- D. 100 km Discuss
Correct Answer: 105 km
Explanation:
Average speed of train = 240/12 = 20 km/h
Average speed of bus = (3/4) x 20 = 3 x 5 = 15 km/h
Required distance = 15 x 7 = 15 km/h
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