please help me with this assignment

A small business makes 3-speed and 10-speed bicycles at two different factories. Factory A produces 163 -speed and 20 10-speed bikes in 'one day while factory B produces 12 3-speed and 2010 -speed bikes daily. It costs $1000/ day to operate factory A and $800/ day to operate factory B. An order for 963 -speed bikes and 140 10-speed bikes has just arrived. How many days should each factory be operated in order to fill this order at a minimum cost? What is the minimum cost