An ordinary annuity has a value of $1,333.85 at the end of 4 years when $150 is deposited every 6 months into an account earning 6% compounded

An ordinary annuity has a value of $1,333.85 at the end of 4 years when $150 is deposited every 6 months into an account earning 6% compounded semiannually. How much interest has been earned?