Open Ended/Closed Credit Math Question?

Question

It’s time to go shopping! You grab your Best Purchase credit card, which has an annual interest rate of 18%. Assume that you have a previous charged balance of $285.76 (before interest has been applied) on the card. On your shopping trip, you purchased three items: a Blu-ray player, two 4-GB flash drives, and a 19-inch flat-screen television. You purchase all the items on your credit card for a total of $352.18. When the bill comes at the end of the month you decide to pay all of the charges. Answer the following questions, showing any needed calculations. (Round all your answers to nearest hundredth or cent.)

•What is the monthly interest rate?
•What are the interest charges on the card? (Calculate only on last month’s unpaid balance)
•What is the total balance on your card?

Answer 1

- The monthly interest rate is 18%/12 = 1.5%

- The interest charges is 285.76*1.5% = 285.76*1.5/100 = 4.2864 or $4.29

- The total balance is 285.76+4.29+352.18 = $642.23

Answer 2

Alright, there are three eight hour shifts throughout the day and no elf is allowed to work more than one shift. If there are 9,000 elves working at the same time, this means they are all part of the same shift, correct? If this is true than those 9,000 elves can't work again for the rest of the day because they are only required one shift. So if there are three shifts and 9,000 are always working at the same time, you would mulitply 9,000 by 3 to get the total number of elves working each day: 27,000 elves. Now if each elf needs cookies during his break, you just multiply 27,000 by 2: 54,000 cookies. So final answers: 27,000 individual elves work every day. 54,000 cookies are needed each day

Answer 3

1.5%