An economy consists of three workers: Sam, Andrew, and Darnell. Each works 10 hours a day and can produce two services: mowing lawns and washing cars. In an hour, Sam can either mow 1 lawn or wash 1 car; Andrew can either mow 1 lawn or wash 2 cars; and Darnell can either mow 2 lawns or wash 1 car. For each of the scenarios listed, determine how many lawns will be mowed and how many cars will be washed per day and enter these values into the corresponding row.

a. All three spend all their time mowing lawns.
b. All three spend all their time washing cars.
c. All three spend half their time on each activity.
d. Sam spends half his time on each activity, while Andrew only washes cars and Darnell only mows lawns.