How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 136 m length?  Select the correct option:	A) 82.1 sec .	B) 12.3 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 + 136 = 246 m . required time = 246 / 20 = 12.3 sec . answer : b"
Answer: B