To find how much will be repaid for this loan, you just multiply the amount of payment by the number of payments
774.5×360=278,820
To find the percentage of this total is total interest, you just divide the total interest by the amount repaid
(78,820÷278,820)×100=28.27%
To find the average amount per payment for interest, you divide the amount of total interest by the number of payments
78,820÷360=218.94
Hope it helps!