Two trains whose lengths are 450 metres and 300 metres are moving towards each other at the speed of 162 km/hr and 108 km/hr respectively. If distance between trains is 300 metres, then in how much time, these trains will cross each other?

A. 14 seconds

B. 28 seconds

C. 35 seconds

D. 21 seconds

Answer: Option A

Solution(By Examveda Team)

$$\eqalign{ & {\text{Time}} = \frac{{450 + 300 + 300}}{{\left( {162 + 108} \right) \times \frac{5}{{18}}}}\,\sec \cr & = \frac{{1050 \times 18}}{{270 \times 5}}\,\sec \cr & = 14\,\sec \cr} $$