Warren Corporation's stock sells for $40 per share. The company wants to sell some 10-year, semi annual coupon payment bond, at $1,000 par value. Each bond would have 40 warrants attached to it, each exercisable into one share of stock at an exercise price of $45. The firm's straight bonds yield to maturity is 10%. Each warrant is expected to have a market value of $5 that the stock sells for $42. What annual coupon rate must be set on the bonds in order to sell the bonds-with-warrants at par value?