What formulas would I use to solve this? Would it be the same for each question? Could someone please explain to me so I can better understand this chapter

Kara Buchanan has decided to start Kara Cleaning, a residential housecleaning service company. She is able to rent cleaning equipment at a cost of $750 per month. Labor costs are expected to be $60 per house cleaned and supplies are expected to cost $5 per house Required a-1. Determine the total expected cost of equipment rental and the average expected cost of equipment rental per house cleaned, assuming that Kara Cleaning deans 25, 35, and 45 houses during one month. (Round "Average per unit" answers to 2 decimal places. No. of Houses Cleaned Total expected rental cost Average per unit rental cost