Harish D. answered 05/01/24
Finance teacher with 3+ years of CFA and Math teaching experience
1.For the car dealer loan,
With down payment of $300, effective loan (P) is 6000-300 = $5700
Also period (n) = 3 yrs = 36 months and rate (r) = 7%
Monthly interest = r/12* P = 7%/12 * 5700 = 33.25
Monthly principal = 5700/36 = 158.33
a. Monthly payment = 33.25 + 158.33 = $191.58
b. Total interest paid = 33.25*36 = $1197
2.For the credit union loan,
With down payment of 10% ($600), effective loan (P) is 6000-600 = $5400
Also period (n) = 3 yrs = 36 months, rate (r) = 8.5% and monthly rate (R) = 8.5/12 = 0.7083%
a. Monthly payment = P / [(1/R)*(1-1/(1+R)^n)] = 5400/[(1/0.007083)*(1-1/(1+0.007083)^36)] = $170.46
b. Total interest paid = 170.46 * 36 - 5400 = $736.6