how long does a train 110 m long running at the speed of 72 km / hr takes to cross a bridge 138 m length ?
speed = 72 * 5 / 18 = 20 m / sec total distance covered = 110 + 138 = 248 m . required time = 248 / 20 = 12.4 sec . answer : b
divide(add(110, 138), multiply(72, const_0_2778))