Question

A 120 m long train crosses a man walking at a speed of 8.5 km/h in the opposite direction in 12 seconds. What is the speed (in km/h) of the train?

• A. 23.3
• B. 27.5
• C. 29.1
• D. 31.5

Answer 1

Answer:

B. 27.5

$S_1+S_2=d/t$

$S_2=8.5kmph$

$d=120m$

$t=12s$

$S_1+8.5=\frac{120}{12}\times \frac{18}{5}$

$S_1+8.5=10\times \frac{18}{5}=36$

$S_1=36-8.5$

$S_1=27.5kmph$