I believe the earnings are $240 for the cars and $200 for the trucks.
If the car wash is $8 and the wax is $12, multiply 12 x 8 = 96 and 12 x 12= 144. Add 144 to 96 to get 240.
If the truck wash is $10 and the wax is $15, multiply 8 x 10 = 80 and 8 x 15 = 120. Add 120 to 80 to get 200. Hope this helps!