A dealer wishes to purchase a number of fans and sewing machines. He

has only Rs 5760to invest and has space for at the most 20 items. A fan costs

him Rs 360 and sewing machine Rs 240. He expects to sell a fan at a profit

of Rs 22 and a sewing machine for a profit of Rs 18. Assuming that he can

sell all the items he buys, how should he invest his money to maximize his

profit. Solve it graphically.