Answer:
9 hours
Step-by-step explanation:
If she makes $ 20 for each car, washing 9 cars in 3 hours would get $ 180.
So she will need to work 9 hours 180 + 180 + 180, washing 9 cars in 3 hours and would get $ 540. This is enough to buy her phone and she will have a surplus of $ 120.
In summary she must work 9 hours
Hope this helps you, please give me the brainliest
