Subject: General Aptitude · Chapter: Problems on Trains · Exam: · Marks: · Difficulty:
What is the speed of the train? (Bank P.O., 2003) I. 280 metres long train crosses a signal pole in 18 seconds. II. 280 metres long train crosses a platform in 45 seconds.
Answer
SELF-PRACTICE — the source book printed no answer.
Nothing is invented here, so this question has no answer on record.
Explanation
Speed $=\frac{\text { Length of the train }}{\text { Time taken to cross the pole }}=\frac{280}{18} \mathrm{m} / \mathrm{s}=\frac{140}{9} \mathrm{m} / \mathrm{s}$. ∴ I alone gives the answer. Speed $=\frac{(280+p)}{45} \mathrm{m} / \mathrm{s}$. But, $p$ = length of platform, is not given. ∴ II is not sufficient to give the answer. ∴ The correct answer is (a).