A company manufactures two products. Each unit of product X requires 10 machine hours and each unit of product Y requires 4 machine hours. The companys productive capacity is limited to 180,000 machine hours. Each unit of product X sells for $15 and has materials costs of $7. Each unit of product Y sells for $8 and has materials costs of $3. Each machine hour costs $0.50. Only considering costs, if the company wants to maximize profit, how many of unit Y should be made?