two trains 137 meters and 163 meters in length are running towards each other on parallel lines , one at the rate of 42 kmph and another at 48 kmpb . in what time will they be clear of each other from the moment they meet
explanation : relative speed of the trains = ( 42 + 48 ) kmph = 90 kmph = ( 90 × 5 / 18 ) m / sec = 25 m / sec . time taken by the trains to ‘ pass each other = time taken to cover ( 137 + 163 ) m at 25 m / sec = ( 300 / 25 ) sec = 12 sec answer : option c
divide(add(137, 163), divide(multiply(add(48, 42), const_1000), const_3600))