Final answer:
A commuter needs to take at least 23 rides in a month to save money by purchasing a $99 unlimited ride card over paying $4.35 per ride.
Step-by-step explanation:
The question asks how many rides are required for a commuter to save money by buying a $99 unlimited ride card instead of paying $4.35 per ride.
To find the break-even point, you divide the cost of the unlimited ride card by the cost per ride.
So, you calculate $99 ÷ $4.35, which is about 22.76. This means that the commuter would need to take at least 23 rides in a month (since you can't take a fraction of a ride) to start saving money with the unlimited ride card.