Problems on Trains Questions

Multiple choice
  1. Quantity I > Quantity II

  2. Quantity I < Quantity II

  3. Quantity I = Quantity II

  4. No relation

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

Train A: Speed = 144 * 5/18 = 40 m/s. Distance = 40 * 8 = 320m. Length = 320 - 200 = 120m. Train B: Speed = 108 * 5/18 = 30 m/s. Distance = 30 * 10 = 300m. Length = 300 - 180 = 120m. Both are 120m.

Multiple choice
  1. 25.3

  2. 26 .67

  3. 28.8

  4. 30

  5. None of these

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

Total distance = 120 + 24 = 144 m. Relative speed = 144 / 12 = 12 m/s. Since they are in opposite directions, relative speed = speed A + speed B. 12 = speed A + 4, so speed A = 8 m/s. 8 m/s = 8 * (18/5) = 28.8 km/h.

Multiple choice
  1. Only statements I and II

  2. Only statements I and III

  3. None of the statements

  4. All three statements

  5. Any two statements

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

To find the sum of the lengths (L1 + L2), we need the relative speed. Statement I gives the time taken to cross. Statement III provides the difference in speeds. We need the actual speeds or the sum of speeds to determine the distance covered (L1 + L2 = relative speed * time). Statements I and III are necessary to relate the lengths to the speeds.

Multiple choice
  1. Any two of the three

  2. Either A or B

  3. Either B or C

  4. All of the three

  5. Only C

Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice
  1. 54

  2. 45

  3. 50

  4. 72

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

Let L be length and v be train speed. (v-2) * 5/18 * 9 = L and (v-4) * 5/18 * 10 = L. (v-2) * 2.5 = (v-4) * 2.777. 2.5v - 5 = 2.777v - 11.11. 0.2777v = 6.11, v = 22. L = (22-2) * 5/18 * 9 = 20 * 2.5 = 50.

Multiple choice
  1. 140 km/hr

  2. 130 km/hr

  3. 110 km/hr

  4. 100 km/hr

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

Relative speed = Total distance / Time = (130 + 120) / 5 = 250 / 5 = 50 m/s. 50 m/s = 50 * 18/5 = 180 km/hr. Since they are moving in opposite directions, relative speed = v1 + v2. 180 = 80 + v2, so v2 = 100 km/hr.

Multiple choice
  1. 4 seconds

  2. 5 seconds

  3. 6 seconds

  4. 7 seconds

  5. None of these

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

Relative speed = 80 - 3 = 77 km/hr = 77 * (5/18) m/s = 385/18 m/s. Time = Distance / Speed = 150 / (385/18) = (150 * 18) / 385 = 2700 / 385 = 7.01 seconds.

Multiple choice
  1. 400

  2. 500

  3. 600

  4. 700

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

Let L be the length of the train and v be its speed. The relative speed against the first person is (v + 10) and against the second is (v + 20). Using distance = speed * time, we have L = 12(v + 10) and L = 10(v + 20). Solving 12v + 120 = 10v + 200 gives 2v = 80, so v = 40. Substituting back, L = 12(40 + 10) = 600.

Multiple choice
  1. 45 km./hr

  2. 50 km./hr

  3. 60 km./hr

  4. 40 km./hr

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

Let the train length be L metres and its speed be v metres per second. Passing a man gives L = 20v, while passing the platform gives L + 100 = 28v. Solving gives v = 12.5 m/s, which equals 45 km/h.

Multiple choice
  1. 806

  2. 82.4

  3. 86.4

  4. 88.6

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

Let lengths be 3x and 5x. Tunnel length = 1.5 * (3x + 5x) = 12x. Speed P = 20 m/s, Speed Q = 15 m/s. Time P = (3x + 12x) / 20 = 15x / 20 = 0.75x. Time Q = (5x + 12x) / 15 = 17x / 15. Difference = 17x/15 - 0.75x = 46 minutes = 2760 seconds. (17x - 11.25x) / 15 = 2760 => 5.75x = 41400 => x = 7200. Tunnel = 12 * 7200 = 86400 meters = 86.4 km.

Multiple choice
  1. 17

  2. 20

  3. 24

  4. 10

Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice
  1. 72 kmph

  2. 80 kmph

  3. 90 kmph

  4. 95 kmph

  5. 108 kmph

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

The relative speed is total distance divided by time: (270 + 270) / 12 = 540 / 12 = 45 m/s. Converting to kmph, 45 * 18/5 = 162 kmph. With a speed ratio of 4:5, the faster train is 5/9 of the total relative speed: 5/9 * 162 = 90 kmph.

Multiple choice
  1. 60 kmph

  2. 66 kmph

  3. 72 kmph

  4. 99 kmph

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

Speed of first train = 150m / 15s = 10 m/s = 36 km/hr. Relative speed of both trains = 150m + 150m / 8s = 300/8 = 37.5 m/s. Relative speed = 37.5 * 3.6 = 135 km/hr. Speed of second train = 135 - 36 = 99 km/hr.