Answer:
20% increase in sales over 50 cars per month
Step-by-step explanation:
The actual increase was 10 cars.
We compare 10 cars to the original 50 sold, and obtain:
10 cars
--------------- = 1/5 or 0.20
50 cars
Multiplying either 1/5 or 0.20 by 100%, we get 20%
