Elise and Ling decide to start a tutoring business. To start their business, they need to invest in buying 2 units of the most recent version of MacBook Pro which costs $2500 for one unit. The cost of hiring employees will be $25,000 per year, cost of office supplies $1000 per year, and the cost for advertising their business will be $4,000 per year. The market interest rate is 20% and suppose the value of the computers does not change over time.
1. What is the least amount of revenue per year they must have expected to start this business?