There are two cars (electric vehicle and gas car) traveling 10,000 km/yr. . The purchase costs are $30,000 for electric vehicle and $25,000 for gas car. The electric vehicle is assumed to travel 5 km on each kWh of electricity ($0.25/kWh). The gas car is assumed to travel 100 km on 10 litre gasoline ($1.50/litre). Historically, electricity rates have risen much more slowly than gasoline prices; the estimated annual rise rates are 3% and 10%, respectively. Due to regenerative braking, the EV brake-pad maintenance costs are lower. The tires and brake are replaced every 3 years. And the replacement costs are $1,500 for electric vehicle and $2,000 for gas car. The annual discount rate is 8%, and the cars are supposed to be owned 7 years before resale. The incomes from vehicle resale are $10,000 for electric vehicle and $12,000 for gas car. Please calculate the net present value of ownership for these two vehicles