The question consists of two statements numbered "I and II" given below it. You have to decide whether the data provided in the statements is sufficient to answer the question.
Find the time taken by a 400-metre-long train to cross a platform of length 1,600 metres.
Statement I: Train can cross a 1,200-metre-long platform in 80 seconds.
Statement II: Train can cross a pole in 20 seconds.
Show answer & explanation
Correct answer: C
Explanation
Given:
Length of the train = 400 m
Length of the platform = 1600 m
According to the formula:
Time = Distance / Speed
Statement I:
Distance covered to cross a 1200 m platform = 400 + 1200 = 1600 m
Time = 80 s
Speed = 1600 / 80 = 20 m/s
Now, for the 1600 m platform, the distance = 400 + 1600 = 2000 m
Time = 2000 / 20 = 100 s
Therefore, Statement I alone is sufficient.
Statement II:
Distance covered to cross a pole = 400 m
Time = 20 s
Speed = 400 / 20 = 20 m/s
Now, for the 1600 m platform, the distance = 400 + 1600 = 2000 m
Time = 2000 / 20 = 100 s
Therefore, Statement II alone is also sufficient.
To answer the question, either Statement I alone or Statement II alone is sufficient.