Question

Amistad deposited $2,163.27 in a savings account that earns 3.9% simple interest. What will Amistad's account balance be in nine months?

Answer 1

let's assume that 3.9% is the annual interest rate (since it's not explicitly stated)

9 months / 1 year = 9 months / 12 months or 3/4 of the annual interest

% means "per 100" so 3.9 % means 3.9 per 100 or (3.9/100)

calculate old balance + (3/4)(interest rate)(old balance) to get the new balance