Problems on Trains Questions

Multiple choice
  1. 2 : 3

  2. 1 : 2

  3. 3 : 2

  4. 2 : 1

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

Let lengths be L1, L2 and speeds be v1, v2. L1/v1 = 27, L2/v2 = 17. (L1+L2)/(v1+v2) = 23. Substituting L1=27v1 and L2=17v2: (27v1 + 17v2)/(v1+v2) = 23. 27v1 + 17v2 = 23v1 + 23v2. 4v1 = 6v2. v1/v2 = 6/4 = 3/2.

Multiple choice
  1. Any one of them is sufficient.

  2. Only A and C together are sufficient.

  3. Only A and B together are sufficient.

  4. Either A alone or B alone is sufficient.

  5. All A, B and C are necessary.

Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice
  1. Statement (A) alone is sufficient, but statement (B) alone is not sufficient.

  2. Statement (B) alone is sufficient, but statement (A) alone is not sufficient.

  3. Both (A) and (B) together are sufficient, but neither of them alone is sufficient.

  4. Each statement alone is sufficient.

  5. Statements (A) and (B) together are not sufficient.

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

Let speeds be v1 and v2. (A) (80+85)/(v1-v2) = 37.5. (B) (80+85)/(v1+v2) = 7.5. We have two equations with two variables, so both are needed to solve for v1 and v2.

Multiple choice
  1. 1

  2. 2

  3. 3

  4. 4

  5. None of these

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

Speed = Distance / Time. Statement I gives the length of the train. Statement II gives the length of the other train and the time taken to pass it. Together, the total distance is 100 + 150 = 250 metres, and time is 5 seconds, so speed = 250 / 5 = 50 m/s. Both are required.

Multiple choice
  1. Only (i) and (ii)

  2. Only (ii) and (iii)

  3. Only (i), (iii) and (iv)

  4. (i), (ii), (iii) and (iv)

  5. Only (i) and (iv)

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

The given data allows solving for L and S using the two time equations (crossing train Y and crossing the tunnel). Once L and S are known, all listed quantities (i) through (iv) can be calculated.

Multiple choice
  1. Only (iii) and (iv)

  2. Only (i), (ii) and (iv)

  3. Only (i), (ii) and (iii)

  4. Only (i) and (iv)

  5. All (i), (ii), (iii) and (iv)

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

Train A speed S, Train B speed S+30. Train B leaves 10h later. Train A meets B at 1800km. Time A = 1800/S. Time B = 1800/(S+30). Time A - Time B = 10. 1800/S - 1800/(S+30) = 10. 180/S - 180/(S+30) = 1. 180(30) = S(S+30). S^2 + 30S - 5400 = 0. (S+90)(S-60) = 0. S = 60. Speed B = 90. We know speeds, so we can find (iii) and (iv).

Multiple choice
  1. The question can be answered by using statement I alone but cannot be answered using the other statement alone.

  2. The question can be answered by using statement II alone but cannot be answered using the other statement alone.

  3. The question can be answered by using either of the statements alone.

  4. The question can be answered using both of the statements together, but cannot be answered using either of the statements alone.

  5. The question cannot be answered even by using both the statements together.

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

To find the time taken to cross the man, we need the relative speed and the length of the train. Statement I gives the man's speed, and Statement II provides the time taken when moving in the same direction, which allows us to calculate the train's length using the relative speed formula. Both statements are required to determine the length of the train and subsequently the time taken to cross the man in the opposite direction.

Multiple choice
  1. Only statements I and II

  2. Only statements I and III

  3. Only statements II and III

  4. All three statements

  5. Only statement II and either statement I or statement III

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

To find the speed, we need the total distance (length of train + length of platform) and the time taken. Statement II gives time. Statement III gives the total distance. Statement I is redundant if III is known. Thus, II and III are sufficient.

Multiple choice
  1. Quantity I = Quantity II or no relation

  2. Quantity I > Quantity II

  3. Quantity I ≥ Quantity II

  4. Quantity I < Quantity II

  5. Quantity I ≤ Quantity II

Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice
  1. Quantity 1 > Quantity 2

  2. Quantity 1 ≥ Quantity 2

  3. Quantity 2 > Quantity 1

  4. Quantity 2 ≥ Quantity 1

  5. Quantity 1 = Quantity 2 or Relation cannot be established

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

Speed = (Length of train + Length of bridge) / Time. For Q1: x = (251 + 149) / 10 = 40. Value = 40 + 0.25*40 = 50. For Q2: y = (251 + 159) / 10 = 41. Value = 2(41) + 0.1*41 = 82 + 4.1 = 86.1. Since 86.1 > 50, Q2 > Q1.