4. Real-world examples, please show your work? a. Suppose Daryl spontaneously treats all his friends to pizza, drinks, and dessert at a dine-in Italian place. He has already spent his excess cash from his paycheck, so he decides to put it on his credit card and pay for it later. The total cost for the pizza for his group of friends, including the tip, is $149.45. His credit card has an interest rate of 21.99%. If he pays $25 per month, how long will it take him to pay for that spontaneous purchase? \begin{tabular}{|c|l|} \hline N & \\ \hline IY & \\ \hline PV & \\ \hline PMT & \\ \hline FV & \\ \hline \end{tabular} b. Let's say Daryl treats his friends a few times during the month and accumulates a debt of 5674.87 on his credit card. His crodit card and has an interest rate of 21.99%. If he pays 525 per month, how long will it take him to pay for this generosity that his friends appreciate but can't currently afford? \begin{tabular}{|c|l|} \hline N & \\ \hline IY & \\ \hline PV & \\ \hline PMT & \\ \hline FV & \\ \hline \end{tabular} c. What does this tell you about credit card usage? What is the risk of using a credit card? When is it a good thing? How can you use a credit card responsibly