how long does a train 100 m long travelling at 60 kmph takes to cross a bridge of 80 m in length ?
"d 16.8 sec d = 100 + 80 = 180 m s = 60 * 5 / 18 = 50 / 3 t = 180 * 3 / 50 = 10.8 sec"
divide(add(100, 80), multiply(60, const_0_2778))