Carrie wants to buy a new iPhone. The new iPhone costs $800. She can trade in her Samsung Galaxy for $240. She can make $80 per week babysitting. How many weeks does she have to work before she can purchase the iPhone? Let's answer step by step:
The total cost of the iPhone will cost Carrie $800 - $240 = $560. It will take her $560 / $80 = 7 weeks to earn enough money. The answer: 7.