A train crosses a pole in 15 s and a platform 100 m long in 25 s. its length…
2024
A train crosses a pole in 15 s and a platform 100 m long in 25 s. its length (in m) is
- A.
60
- B.
100
- C.
150
- D.
200
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Correct answer: C
Let the length of the train be D meters.
Speeds when crossing the pole and the platform are equal, so set up the equation: D/15 = (D + 100)/25
Multiply both sides by 75 (or cross-multiply): 25D = 15(D + 100).
Expand and simplify: 25D = 15D + 1500 → 10D = 1500.
Solve for D: D = 150.
Therefore the length of the train is 150 m.