two trains each 250 m in length are running on the same parallel lines in opposite directions with the speed of 80 kmph and 60 kmph respectively . in what time will they cross each other completely ?
"explanation : d = 250 m + 250 m = 500 m rs = 80 + 60 = 140 * 5 / 18 = 350 / 9 t = 500 * 9 / 350 = 12.9 sec answer : option d"
divide(250, multiply(80, const_0_2778))