the speed of a boat in still water in 20 km / hr and the rate of current is 4 km / hr . the distance travelled downstream in 24 minutes is :
"speed downstream = ( 20 + 4 ) = 24 kmph time = 24 minutes = 24 / 60 hour = 2 / 5 hour distance travelled = time × speed = 2 / 5 × 24 = 9.6 km answer is d ."
multiply(add(20, 4), divide(24, const_60))