Set up the proportion with the numbers on top equalling the cars and the numbers on the bottom representing the trucks.
[tex] \frac{8}{36} = \frac{c}{9} [/tex]
c equals the number of unknown cars.
To solve the proportion, cross multiply (multiply 8 by 9 and 36 by c) and solve for c.
72 = 36c
Divide 36 from both sides to get the answer.
c = 2
If there are 9 trucks, there are 2 cars.
You can check this by dividing 2 by 9, and dividing 8 by 36. Since they both equal the same number, this answer is correct.
Hope this helps =)
