Final answer:
To earn enough money to purchase the phone, Antonette needs to work 10 hours.
Step-by-step explanation:
To calculate the number of hours Antonette needs to work to earn enough money to purchase the phone, we need to divide the cost of the phone by the amount she earns shoveling driveways per hour.
Antonette earns $10.00 for each driveway she shovels and she can shovel 2 driveways in 1 hour, so her earnings per hour are $10.00 x 2 = $20.00.
If the phone costs $200.00, Antonette will need to work $200.00 / $20.00 = 10 hours to earn enough money to purchase the phone.
Therefore, Antonette needs to work 10 hours to earn enough money to purchase the phone.