10. Pablo was reviewing the water bill for his carwash business and determined that the highest bill, $5,400, occurred in July when 2,700 cars were washed and the lowest bill, $3,100, occurred in February when 1,500 cars were washed. What was the variable cost per carwash? a. $2.00 b . $1.92 C. $2.07 d. $1.15