two trains 121 meters and 153 meters in length respectively are running in opposite directions , one at the rate of 80 km and the other at the rate of 65 kmph . in what time will they be completely clear of each other from the moment they meet ?
"t = ( 121 + 153 ) / ( 80 + 65 ) * 18 / 5 t = 6.8 answer : b"
divide(add(121, 153), multiply(add(80, 65), const_0_2778))