Problems on Trains Questions

Multiple choice
  1. 45 km/hr.

  2. 40 km/hr.

  3. 25 km/hr.

  4. 30 km/hr.

  5. 90 km/hr.

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

To find the speed: Let train length = L meters and speed = v m/s. Crossing a 100m platform in 14s means L + 100 = 14v. Crossing a man (train length only) in 10s means L = 10v. Substituting: 10v + 100 = 14v, so 4v = 100, v = 25 m/s. Convert to km/hr: 25 × (18/5) = 90 km/hr. This matches option E.

Multiple choice
  1. Any two

  2. I and either II or III

  3. Any one

  4. Only III

  5. Only II

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

From I and II: Platform length = (25+5) × 5/18 × 12 = 100 m train length. Then from I: 100 + platform = 25 × 5/18 × 18 = 125, so platform = 25 m. From I and III: Train length = 25 × 5/18 × 14.4 = 100 m, same calculation. Either II or III gives train length when combined with I. III alone gives only train length (100 m), not platform. II alone is insufficient without train speed from context.

Multiple choice
  1. Only A

  2. Only B

  3. Only C

  4. Only B and C

  5. All A, B, C are required to answer the question

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

From C: Train speed = 250 meters / 10 seconds = 25 m/s = 90 km/hr. From B: Distance = 780 km, departure = 9:00 am. Time = 780/90 = 8.67 hours = 8 hours 40 minutes. Arrival time can be calculated. Statement A about crossing another train is irrelevant. So only B and C are needed.

Multiple choice
  1. 8 sec

  2. 9 sec

  3. 23 sec

  4. 25 sec

  5. Cannot be determined

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

The problem is missing critical information: the man's position on the platform (where he starts or is located when the train begins crossing) and whether he is stationary or moving. Without knowing the relative positions of the train and man, the crossing time cannot be uniquely determined.

Multiple choice
  1. If statement I alone is sufficient but statement II alone is not sufficient.

  2. If statement II alone is sufficient but statement I alone is not sufficient.

  3. If each statement alone (either I or II) is sufficient.

  4. If statement I and II together are not sufficient.

  5. If both statements I and II together are sufficient, but neither statement alone is sufficient.

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

Statement I gives only train length (120 m), insufficient without time. Statement II mentions crossing another 180 m train in 4 seconds, but lacks direction information (same or opposite direction) and speed of the other train. Combined, we still need the other train's speed or direction.

Multiple choice
  1. All are necessary

  2. All together are not sufficient

  3. Only II and III

  4. Only I and II

  5. None of these

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

To find the speed of the first train, we need distance covered and time taken. When trains move in opposite directions, relative speed = sum of individual speeds. Distance = sum of lengths (100m + 180m = 280m), time = 72 seconds. So relative speed = 280/72 m/s. But we need the speed of the FIRST train specifically, not just relative speed. Without knowing the second train's speed, we cannot determine the first train's speed. The statements are insufficient.

Multiple choice
  1. 111 sec./से.

  2. 119 sec./से.

  3. 131 sec./से.

  4. 121 sec./से.

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

Train lengths from pole crossing: L₁ = 14 × 7k = 98k units, L₂ = 16 × 9k = 144k units. When moving in same direction, relative speed = 9k - 7k = 2k. Time to cross = (98k + 144k) / 2k = 121 sec.

Multiple choice
  1. 5 m./sec.(मी./से.)

  2. 8 m./sec.(मी./से.)

  3. 10 m./sec.(मी./से.)

  4. 12 m./sec.(मी./से.)

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

Train speed = 108 km/hr = 30 m/s. Train + platform length = 30 × 12 = 360 m. So platform = 360 - 280 = 80 m. Man's speed = 80/10 = 8 m/s.

Multiple choice
  1. 300 m/मी.

  2. 350 m/मी.

  3. 400 m/मी

  4. 450 m/मी.

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

Convert speeds to m/s: 48 km/hr = 40/3 m/s and 42 km/hr = 35/3 m/s. When trains cross in opposite directions, their relative speed is the sum: 40/3 + 35/3 = 25 m/s. Distance covered in 12 seconds = 25 × 12 = 300 m, which equals the sum of both train lengths (L + L/2 = 1.5L). So 1.5L = 300 m, giving L = 200 m. For the platform crossing: distance = 200 + platform_length. Using 40/3 m/s and 45 seconds, we get 200 + platform_length = (40/3) × 45 = 600 m, so platform_length = 400 m.

Multiple choice
  1. 100

  2. 120

  3. 160

  4. 240

  5. 250

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

When a train crosses a pole, distance traveled equals its length. When crossing a platform three times its length, total distance is 4× length. Time difference = (4L - L)/20 = 3L/20 seconds. Given this equals 24 seconds: 3L/20 = 24, so L = 160 meters.

Multiple choice
  1. 170 km/hr किमी/घंटा

  2. 100 km/hr किमी/घंटा

  3. 110 km/hr किमी/घंटा

  4. 50 km/hr किमी/घंटा

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

Total distance to cover = 132 + 176 = 308 m = 0.308 km. Time = 0.168 min = 0.0028 hr. Relative speed = 0.308/0.0028 = 110 km/hr. First train speed = relative speed + second train speed = 110 + 60 = 170 km/hr.

Multiple choice
  1. 40 km/hr

  2. 45 km/hr

  3. 50 km/hr

  4. 54 km/hr

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

First train's speed = 150m/15s = 10 m/s. When trains cross in opposite directions, relative speed = sum of speeds. Total distance = 150 + 150 = 300m. Time = 12s, so relative speed = 300/12 = 25 m/s. Second train's speed = 25 - 10 = 15 m/s = 15 × (18/5) = 54 km/hr. The key is understanding relative speed in opposite directions.

Multiple choice
  1. 50 km/hr.

  2. 54 km/hr.

  3. 60 km/hr.

  4. 64 km/hr.

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

When trains move in opposite directions, their relative speed is the sum of individual speeds. Total distance to cover = 108 + 112 = 220 m. Time taken = 8 seconds. Relative speed = 220/8 = 27.5 m/s = 27.5 × (18/5) = 99 km/hr. If one train's speed is 45 km/hr, the other train's speed = 99 - 45 = 54 km/hr.