a boat takes 3 hours to go 12 miles upstream. it can go 18miles downstream in the same time. find the rate of the current and the rate of the boat in...

a boat takes 3 hours to go 12 miles upstream. it can go 18miles downstream in the same time. find the rate of the current and the rate of the boat in still water. (hint: because the current pushes the boat when it is going downstream, the rate of the boat downstream is the sum of the rate of the boat and the rate of the current. the current slows down the boat when it is going upstream, so the rate of the boat upstream is the difference of the rate of the boat and the rate of the current)

The rate of the current is ___ miles per hour

the rate of the boat in still water is ___ miles per hour.