Question. James gets paid $0.50/mile to drive a truck carrying hazardous waste. He has to pay $4.00/gallon for gas and his truck gets 20 miles per gallon. How much profit does he make from a 600 mile trip?
Answer. 180
What step-by-step reasoning justifies that answer?
Reasoning: First find the total payment James receives: $0.50 / mile * 600 miles = $300. Then find how many gallons of gas he needs to buy: 600 miles / 20 miles / gallon = 30 gallons. Then multiply that number by the price of gas per gallon to find the total cost of the gas: $4.00 / gallon * 30 gallons = $120. Then subtract that amount from James' earnings to find his profit: $300 - $120 = $180.