Answer:
81 blue cars
Step-by-step explanation:
Total Cars = 90
How much % are blue = 90
=> 90 x 90/100 = How many cars are blue
=> 8100/100 = the number of cars that were blue
=> 81 = cars that were blue.
There 81 blue cars in the parking lot.
9.50 X 2 = 19
19 + 4 = 13
13/100 X 106 = 13.78
13.78-13 = 0.78
sales tax = 0.78