A train crossesa a bridge of length 171 m in 27 second. It passed a pedestrain, running in the opposite direction with a speed 1m/s, in 9s. Find the velocity and the length of the train.

Options

A. 20 m/s, 189 m
B. 10 m/s, 99 m
C. 15 m/s, 144 m
D. 12 m/s, 165 m

Answer

B

Explanation

`(171+l)/v=27`
`l/(1+v)=9`
`l=9+9v`
`rArr 180+9v=27v`
v=10 m/s
l=99