(second question of 2 that i need help with)

A $25000 loan is repaid over 8 years with monthly instalments of $391. What was the interest rage (p.a.) changed on the loan?

2 answers

Po = $25,000.

t = 8yrs. * 12mo./yr. = 96 mo.

P = 391/mo. * 96mo. = $37,536.

Int./yr. = (P-Po)/t = (37,536-25,000)/8yrs. = $1567.

APR
APR = (1567/37,536)*100 = 4.17%.