How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 142 m length?
Options.
A) 82.1 sec . B) 12.6 sec C) 19.1 sec . D) 17.1 sec . E) 42.1 sec .

Rationale: "speed = 72 * 5 / 18 = 20 m / sec total distance covered = 110 + 142 = 252 m . required time = 252 / 20 = 12.6 sec . answer : b"
Answer: B