Interest of $22.05 was earned in three months on a balance of $1960. What is the interest rate per annum earned on that account?

P.s please explain how you solved it.

1 answer

annual interest = 4*22.05=88.20

$1960 earns 88.20 interest in one year, so annual interest,
i=88.05/1960=0.045, or 4.5% per annum