two trains 200 m and 160 m long run at the speed of 68 kmph and 40 kmph in opposite directions in parallel tracks . the time which they take to cross each other is ?
"relative speed = 68 + 40 = 108 kmph * 5 / 18 = 30 m / s distance covered in crossing each other = 200 + 160 = 360 m required time = 360 * 1 / 30 = 12 sec answer is d"
divide(add(200, 160), multiply(add(68, 40), const_0_2778))