This is the question:

"First Inc. is considering the possibility of refunding its 40-year $200 million outstanding bond issue. The coupon rate of the old issue is 14% (assume all coupons are paid annually in this question) and was issued 20 years ago. It can be refunded with a new 20-year $200 million issue at a coupon rate of 10%. A call premium of 8% will have to be paid and floatation costs on the new issue are expected to be $6 million. The new bonds will have to be issued one month before the old bonds are called and the proceeds can be parked in the money market to earn 6% (compounded monthly). The company's tax rate is 30%. Calculate the NPV of the proposed refunding."

Where I have trouble is figuring out how to get the discount rate to calculate PV of flotation cost tax savings