Water sold x unit price – fixed fee = revenue
The price of water sold by the automatic sales machine is 0.2 yuan/liter per barrel calculated by 20 liters, that is, 3 yuan/barrel. If every 30 barrels sold is calculated by 30 days per month, the average benefit is:
1, Monthly turnover :3 yuan/barrel x30 barrels/day x30 days =2700 yuan
2, monthly expenses: site fee 100 yuan, water and electricity 320 yuan total :420 yuan
3, monthly net income :2700 yuan -420 yuan =2280 yuan
4, annual net income :2280 yuan/month x12 months =27360 yuan
