Answer:
$8,20
Step-by-step explanation:
The APR (annual percentage rate) is the interest rate you will pay in one year. In this case, the problem asks for the interests saved in the first month, then, we must convert both annual rates in monthly rates with this formula:
Monthly rate= ((1+annual rate)^(1/# periods))-1
Monthly rate(credit card)= ((1+16.65%)^(1/12))-1
Monthly rate (credit card)= 1.29%
Monthly rate(friend)= ((1+3.25%)^(1/12))-1
Monthly rate(friend)=0.27%
Interest first payment with monthly rate (credit card) = $880.00*1.29%= $10.33
Interest first payment with monthly rate (friend)= %800*0.27% = $2.13
She or he saved: $10.33-$2.13= $8,20