Problems on Trains Questions

Multiple choice
  1. 17 sec/सेकेण्ड

  2. 13 sec/सेकेण्ड

  3. 15 sec/सेकेण्ड

  4. 12 sec/सेकेण्ड

  5. 19 sec/सेकेण्ड

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

First train length = 54 × (5/18) × 8 = 120 m. Second train length = 72 × (5/18) × 15 = 300 m. Total length = 420 m. Relative speed (opposite direction) = 54 + 72 = 126 km/hr = 126 × (5/18) = 35 m/s. Time to cross each other = 420/35 = 12 seconds. Option D is correct.

Multiple choice
  1. 100 km/hr

  2. 120 km/hr

  3. 90 km/hr

  4. cannot be determined

  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

After crossing, if trains take t1 and t2 hours to reach destinations, speed ratio is √t2 : √t1. Here t1 = 16, t2 = 9. So v1 : v2 = √9 : √16 = 3 : 4. Given v1 = 90 km/hr, then v2 = (4/3) × 90 = 120 km/hr.

Multiple choice
  1. 160 m

  2. 180 m

  3. 140 m

  4. 200 m

  5. None of these इनमे से कोई नहीं

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Train 1: 72 km/hr = 20 m/s. In 18 seconds, distance = 360 m. Length of train 1 = 360 - 160 = 200 m. Train 2: 90 km/hr = 25 m/s. In 15 seconds, distance = 375 m. Length of train 2 = 375 - 160 = 215 m. The question asks for the length of the other train (215 m), which is not listed in options A-D. Hence, option E is correct.

Multiple choice
  1. 10 sec

  2. 12 sec

  3. 14 sec

  4. 15 sec

  5. 16 sec

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total distance to be covered = sum of train lengths = 137 + 163 = 300 m. Relative speed when moving towards each other = 42 + 48 = 90 km/hr = 90 × 5/18 = 25 m/s. Time = Distance/Speed = 300/25 = 12 seconds. The trains will be clear of each other in 12 seconds from the moment they meet.

Multiple choice
  1. 58

  2. 60

  3. 62

  4. 68

  5. 72

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Speed ratio 5:8, time ratio 4:3 for crossing a pole (distance = length). Length = speed × time. Length ratio = (5×4):(8×3) = 20:24 = 5:6. Parts sum to 11, total length 660, so parts are 60 each. Lengths are 300 and 360. Difference = 60.

Multiple choice
  1. 10.8

  2. 25

  3. 7

  4. 11.2

  5. None of these इनमें से कोई नहीं

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let train length = L, speed = v. For platform: 2L = v × 300 sec (5 min). For man: L = (v-2) × 420 sec (7 min). From first: L = 150v. Substitute: 150v = (v-2) × 420, so 150v = 420v - 840, giving 270v = 840, v = 28/9 m/s. In km/h: (28/9) × 3.6 = 11.2 km/h. Answer D is correct.

Multiple choice
  1. 35 km/hr

  2. 45 km/hr

  3. 20 km/hr

  4. data inadequate

  5. None of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let train length = L meters, speed = v kmph. Speed in m/s = v × 5/18. Overtaking person at 2kmph: relative speed = (v-2) × 5/18 m/s. Time = 8s, so L = 8(v-2)(5/18). Overtaking person at 4kmph: relative speed = (v-4) × 5/18 m/s. Time = 9s, so L = 9(v-4)(5/18). Equating: 8(v-2) = 9(v-4), giving 8v - 16 = 9v - 36, so v = 20 kmph.

Multiple choice
  1. 10 sec

  2. 12 sec

  3. 14 sec

  4. 15 sec

  5. 16 sec

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total distance to cross = 137 + 163 = 300 m. Relative speed = 42 + 48 = 90 km/hr = 90 × 5/18 = 25 m/s. Time = 300/25 = 12 seconds. This matches option B exactly.

Multiple choice
  1. 300 m

  2. 400 m

  3. 360 m

  4. 280 m

  5. 320 m

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Train A: speed = 86.4 km/h = 24 m/s. Length = LA, crosses tower in t seconds, so LA = 24t. Train B: speed = 108 km/h = 30 m/s, length LB = 2LA (100% more), crosses 80m platform in 2t seconds. So LB + 80 = 30 × 2t = 60t. Substituting LB = 2LA = 2 × 24t = 48t: 48t + 80 = 60t, giving 12t = 80, so t = 20/3. Then LB = 48 × (20/3) = 320m. Option E is correct.

Multiple choice
  1. M, 120

  2. U, 130

  3. U, 120

  4. M, 130

  5. None of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Train M: 150m at 54 kmph = 15 m/s. Train U: 250m at 90 kmph = 25 m/s. Tunnel length: 300m. Time for M to exit tunnel = (150+300)/15 = 450/15 = 30s. Time for U to exit tunnel = (250+300)/25 = 550/25 = 22s. So U exits first. At 22s, M has traveled: 22 × 15 = 330m. M's tail (end) has entered the tunnel at: 330 - 150 = 180m from tunnel entrance. Tunnel length remaining for M: 300 - 180 = 120m. Therefore, when U exits, 120m of M is still in the tunnel. Answer C (U, 120) is correct.

Multiple choice
  1. 26(2/3)%

  2. 16(2/3)%

  3. 20(2/3)%

  4. 26%

  5. 18%

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For trains to exit simultaneously, their effective crossing times must equalize. With original speeds 54 and 90 kmph, times are 8.33s and 4.44s. Setting 300/(v+54) = 300/90 and solving gives new speed v = 66 kmph, requiring reduction of 24 kmph, which is 26(2/3)% of 90.