Train P crosses an electric pole in 30 seconds and the speed of the Train Q is 18 kmph more than the speed of the Train P. If train P crosses train Q is running in opposite directions in 20 seconds and also crosses 200 m long tunnel in 40 seconds. Then find the length of the Train Q ?
This questions was previously asked in
RRB PO Prelims (06 Aug 2023, Shift 4)
300 meters
Correct Answer350 meters
Incorrect Answer450 meters
Incorrect Answer400 meters
Incorrect Answer500 meters
Incorrect AnswerExplanation:
- Let the length of Train P = L meters.
- Train P crosses a pole in 30 s ? speed of P = L/30 m/s.
- Train P crosses 200 m tunnel in 40 s ? (L + 200)/40 = L/30 ? 30(L + 200) = 40L ? 30L + 6000 = 40L ? 10L = 6000 ? L = 600 meters.
- So, speed of P = 600/30 = 20 m/s = 72 kmph.
- Speed of Q is 18 kmph more = 90 kmph = 25 m/s.
- They run in opposite directions, combined speed = 20 + 25 = 45 m/s.
- They cross in 20 s: (Length of P + Length of Q)/20 = 45 ? (600 + Length of Q) = 900 ? Length of Q = 300 meters.
- Correct Option: 1, 300 meters
- All other options do not fit the calculation.
- Option 2, 3, 4, 5 are incorrect.
- The correct length of Train Q is 300 meters.
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By: Parvesh Mehta