Question

Laura owes $4759 on a credit card with a 20.9% interest rate compounded monthly. What is the monthly payment she should make in order to pay off this debt in 3 years, assuming she does not charge any more purchases with the card?

Answer 1

This can be calculated using the formula:
P = L((r/n)*(1 + r/n)^(n*t))/((1 + r/n)^(n*t) - 1)
Where:
L = 4759
r = 0.209
n = 12
t = 3
So plugging in our data:P = 4759((0.209/12)*(1 + 0.209/12)^(12*3))/((1 + 0.209/12)^(12*3) - 1)
Which will give us the amount of: $179.05 is the monthly repayments.
Other info:
Total interest:$1,686.80
Total cost:$6,445.80

Answer 2

$4759:100%=$x:120.9%, 100*x=4759*120.9, x=(4759*120.9)/100, x=$5759.631  
With interest rate Laura owes $5759.31.
3yr*12mo=36mo
$5759/36mo=159.972$/mo
Laura's monthly payment is $159.972