The brick has a no payment and no interest policy for 1.5 years on all purchases over $1000. Recently, I purchased a sofa, love seat, dining room set and bedroom set for a total purchase of $5642.32. I noted at the time that the rate or interest was 5.06% per year compounded semi-annually.

a) What amount should I have offered to pay them today for my purchase?

b) If the Brick offers to accept 3708.50, what semi-annually compounded rate would they be offering me?