1..A boat takes 3 hours to go 9 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 goingupstream, so the rate of the boat upstream is the difference of the rate ofthe boat and the rate of thecurrent.)The rate of the current is.................................................................................................................... mile(s) per hour.

2.The sum of two numbers is 195.The difference between them is 21.Find the two numbers.Let x =first number and y=the number.Write two equations. Suppose xgreater than>y. The first equation is x+y=195. the equation is....................................................................