You are the chief financial advisor to a corporation that owns an office complex consisting of 50 units. At $400 per month, every unit can be rented. However for each $20 per month increase, there will be two vacancies with no possibility of filling them The corporation wants to receive a total of $20,240 per month from rents in the complex. You are asked to determine the rent that should be charged for each unit. What is your reply?