This equates to nearly 900 hours of instruction per year, which is similar to or less than many U.S. states, including Florida, New York, Texas, and Massachusetts. At the middle school level (grades 6-8), Chinese students attend just under 1,000 hours of school per year, a figure similar to that of most U.S. states.
1 Hiring a professional pressure-washer costs about $0.08-$0.35 per square foot (depending on local rates), but can go as high as $0.40-$0.80 a square foot depending on the amount and type of stains, dirt, mold or other problems. Buying a basic residential pressure washer with an electric motor starts around $70-$200, depending on size and capacity. 2  A gas-powered residential model usually has a higher pressure rating than an electric machine, and is about $300-$1,000.
Cost breakdown. Labor: armed with an arsenal of safe, fuel emission solvents to remove the oil stains and black haze, professional pressure washers are ideal for pressure washing a driveway. Professional pressure washing will cost between $60-$100 per hr. An area of less than 100 sq.ft. will take about 1 hour for a total cost of between $60-$100. Equipment rental: pressure washing a driveway is possible to do as a DIY style project. Rent a pressure washer from most hardware stores like Home Depot and Lowes with a $100-$150 deposit for $76-$99 per day.