how long does a train 120 m long running at the speed of 70 km / hr takes to cross a bridge 150 m length ?
"speed = 70 * 5 / 18 = 19.4 m / sec total distance covered = 120 + 150 = 270 m . required time = 270 / 19.4 ' = 13.9 sec . answer : b"
divide(add(120, 150), multiply(70, const_0_2778))