Given is the borrowed amount = 380 dollars.
Repayment period = 6 months.
Monthly installments = 67 dollars.
After six months, total repaid amount would be sum of all six monthly installments i.e. 6 x 67 = 402 dollars.
The interest to be paid on this loan would be difference of total repaid amount and borrowed amount.
Interest paid = Repaid amount - Borrowed amount
Interest = 402 dollars - 380 dollars
Interest = 22 dollars.
So, he would pay 22 dollars as interest on this loan.