A train speed past a pole in 15 seconds and a platform 100 m long in 25…
2025
A train speed past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is:
- A.
150 mts
- B.
125 mts
- C.
165 mts
- D.
112 mts
Attempted by 15 students.
Show answer & explanation
Correct answer: A
Solution: find the train length.
Let L be the length of the train in metres.
Passing a pole in 15 s means speed = L / 15 (m/s).
Passing a 100 m platform in 25 s means (L + 100) / speed = 25.
Substitute speed: (L + 100) / (L/15) = 25 ⇒ 15(L + 100) = 25L.
Solve: 15L + 1500 = 25L ⇒ 1500 = 10L ⇒ L = 150.
Answer: 150 mts