two trucks each 250 m long are running in opposite directions on parallel paths . their speeds are 30 km / hr and 20 km / hr respectively . find the time taken by the slower train to pass the driver of the faster one ?
relative speed = 20 + 30 = 50 km / hr . 50 * 5 / 18 = 125 / 9 m / sec . distance covered = 250 + 250 = 500 m . required time = 500 * 9 / 125 = 36 sec . answer : e
divide(multiply(250, const_2), multiply(add(30, 20), const_0_2778))