Question

A train, 240 m long crosses a man walking along the line in opposite direction at the rate of 3 kmph in 10 seconds. The speed of the train is

• A. 63 kmph
• B. 75 kmph
• C. 83.4 kmph
• D. 86.4 kmph

Answer 1

Answer: (C)

83.4 kmph

Given that,
Length of train = 240 m
Speed of man = 3 km/hr
Time taken = 10 seconds
Let speed of train be x kmph
We know that,
Relative speed = $\frac{Lengthoftrain}{Timetaken}$
(x + 3) $\frac{\frac{240}{1000}}{\frac{10}{60\times 60}}=\frac{24\times 60\times 60}{100\times 10}$

(x + 3) = 86.4
x = 86.4 3 $\Rightarrow$ x = 83.4
Hence, speed of train is 83.4 kmph.