Sara owes $12100 upon graduation with monthly interest payments, $10000 without, pays $263.61/month with interest, $225.46/month without, and pays $3717/$3528 interest respectively.
How is that so?
Part a: Amount owed with monthly interest payments
Calculate the total loan amount: $5500 + $4500 = $10000
Calculate the monthly interest rate: 6% / 12 = 0.5%
Calculate the number of interest periods before graduation: 4 years * 12 months/year - 6 months (summer term) = 42 months
Calculate the interest accrued during school: $10000 * 0.005 * 42 = $2100
Add the accrued interest to the loan amount: $10000 + $2100 = $12100
Sara owes $12100 upon graduation if she pays off monthly interest during school.
Part b: Amount owed with no interest payments
Simply add the loan amounts: $5500 + $4500 = $10000
Sara owes $10000 if she pays no interest at all during her school years.
Part c: Monthly loan repayment
Use the loan repayment formula: Monthly Payment =

- P is the loan amount ($12100 for part a and $10000 for part b)
- r is the monthly interest rate (0.005)
- n is the total number of payments (60 months)
Calculate the monthly payment with interest:

Calculate the monthly payment with no interest:
Monthly payment with interest repaid each month is $263.61.
Monthly payment with no interest repaid is $225.46.
Part d: Total interest repaid with different scenarios
Interest with payments during school:
Calculate the total loan payment: $263.61 * 60 months = $15816.60
Calculate the total interest paid: $15816.60 - $12100 = $3716.60 (round to nearest dollar)
Interest with no payments during school:
Calculate the total loan payment: $225.46 * 60 months = $13527.60
Calculate the total interest paid: $13527.60 - $10000 = $3527.60 (round to nearest dollar)
The total interest with interest paid while in school is $3717.
The total interest with no interest paid while in school is $3528.