OK.
Gallons = 1,200 X 0.75 X 10 = 9,000 This makes sense, but our number is closer to a average of 20,000 gasoline gallons a day.
Cars per day = 9,000 / 150 (conservative gas wash rate) = 60 Hmmm. Where does the 150 come from? Is it one wash for every 150 gallons sold? If so we'd be at 130 cars...