7. Loan amount = $12000
Monthly payment = $380
Duration of the repayment = 3 years = 3(12) = 36 months.
Total amount Jason repaid = 36 × 380 = 13680
Interest on loan amount = amount repaid - loan amount
= 13680 - 12000
= 1680
Hence, total amount Jason paid in interest on loan = $1680 and the correct option is (D).
8. Loan amount = $35000
Monthly payment = $315
Duration of the repayment = 10 years = 10(12) = 120 months.
Total amount Gerald repaid = 120 × 315 = 37800
Interest on loan amount = amount repaid - loan amount
= 37800 - 35000
= 2800
Hence, total amount Gerald paid in interest on loan = $2800 and the correct option is (B).