how long does a train 100 m long running at the speed of 80 km / hr takes to cross a bridge 142 m length ?
"speed = 80 * 5 / 18 = 22.2 m / sec total distance covered = 100 + 142 = 242 m . required time = 242 / 22.2 ' = 10.9 sec . answer : b"
divide(add(100, 142), multiply(80, const_0_2778))