a man swims downstream 24 km and upstream 12 km taking 6 hours each time , what is the speed of the man in still water ?
"24 - - - 6 ds = 4 ? - - - - 1 12 - - - - 6 us = 2 ? - - - - 1 m = ? m = ( 4 + 2 ) / 2 = 3 answer : e"
divide(add(divide(12, 6), divide(24, 6)), const_2)