Final answer:
Kate will earn $50 for 5 cars she washed
Step-by-step explanation:
In this problem, Kate earns $120 for 12 cars she washed. Since the amount Kate earns varies directly with the number of cars she washed, we can set up a proportion to find out how much she will earn for 5 cars.
We can set up the proportion:
12 cars / $120 = 5 cars / x
Cross multiplying, we get:
12 * x = 5 * $120
Simplifying, we have:
x = (5 * $120) / 12
x = $50
Therefore, Kate will earn $50 for 5 cars.