a man rows his boat 80 km downstream and 38 km upstream , taking 3 hours each time . find the speed of the stream ?
"speed downstream = d / t = 80 / ( 3 ) = 27 kmph speed upstream = d / t = 38 / ( 3 ) = 9 kmph the speed of the stream = ( 27 - 9 ) / 2 = 9 kmph answer : b"
divide(subtract(divide(80, 3), divide(38, 3)), const_2)