how long does a train 105 m long running at the speed of 68 km / hr takes to cross a bridge 90 m length ?
"speed = 68 * 5 / 18 = 19 m / sec total distance covered = 105 + 90 = 205 m . required time = 205 / 19 = 10.7 sec . answer : b"
divide(add(105, 90), multiply(68, const_0_2778))