A train, 110 m long is running at a speed of 60 km/hr. How many seconds does it take to cross another train, 170 m long, standing on parallel track?
15.6
16.8
17.2
18
Solution
Speed of the Train = 60 km/hr
$=\dfrac {60\times 5}{18} = \dfrac {50}{3}$m/sec
Time to cross the 170 metre long train
$\Rightarrow~ \dfrac {170 + 110}{\dfrac {50}{3}}\Rightarrow~\dfrac {280\times 3}{50}$
$\Rightarrow~\dfrac {84}{5} = 16.8$ second