how many seconds will a train 100 meters long take to cross a bridge 150 meters long if the speed of the train is 72 kmph ?
"d = 100 + 150 = 250 s = 72 * 5 / 18 = 20 mps t = 250 / 20 = 12.5 sec answer : e"
divide(add(150, 100), multiply(72, const_0_2778))