question 8 of 10\njoan has a credit card that uses the previous - balance method. the opening balance of one…

question 8 of 10\njoan has a credit card that uses the previous - balance method. the opening balance of one of her 30 - day billing cycles was $6390, but that was her balance for only the first 3 days of the billing cycle, because she then paid off her entire balance and didnt make any new purchases. if her credit cards apr is 17%, which of these expressions could be used to calculate the amount joan was charged in interest for the billing cycle?\n\na. $\\left(\\frac{0.17}{365}\\cdot30\\right)\\left(\\frac{3\\cdot6390 + 27\\cdot0}{30}\\right)$\nb. $\\left(\\frac{0.17}{365}\\cdot30\\right)(6390)$\nc. $\\left(\\frac{0.17}{365}\\cdot30\\right)\\left(\\frac{3\\cdot0+27\\cdot6390}{30}\\right)$\nd. $\\left(\\frac{0.17}{365}\\cdot30\\right)(0)$

question 8 of 10\njoan has a credit card that uses the previous - balance method. the opening balance of one of her 30 - day billing cycles was $6390, but that was her balance for only the first 3 days of the billing cycle, because she then paid off her entire balance and didnt make any new purchases. if her credit cards apr is 17%, which of these expressions could be used to calculate the amount joan was charged in interest for the billing cycle?\n\na. $\\left(\\frac{0.17}{365}\\cdot30\\right)\\left(\\frac{3\\cdot6390 + 27\\cdot0}{30}\\right)$\nb. $\\left(\\frac{0.17}{365}\\cdot30\\right)(6390)$\nc. $\\left(\\frac{0.17}{365}\\cdot30\\right)\\left(\\frac{3\\cdot0+27\\cdot6390}{30}\\right)$\nd. $\\left(\\frac{0.17}{365}\\cdot30\\right)(0)$

Answer

Answer:

A. $\left(\frac{0.17}{365}\cdot30\right)\left(\frac{3\cdot$6390 + 27\cdot$0}{30}\right)$

Explanation:

Step1: Calculate daily interest rate

The APR is 17% or 0.17. The daily - interest rate is $\frac{0.17}{365}$. For a 30 - day billing cycle, the interest factor is $\frac{0.17}{365}\cdot30$.

Step2: Calculate average daily balance

The balance of $6390 was held for 3 days and $0 for 27 days. The average daily balance formula for a 30 - day cycle is $\frac{3\cdot$6390+27\cdot$0}{30}$.

Step3: Calculate interest

The interest charged is the product of the interest factor and the average daily balance, which is $\left(\frac{0.17}{365}\cdot30\right)\left(\frac{3\cdot$6390 + 27\cdot$0}{30}\right)$.