4) Your firm spends $5,000 every month on printing and mailing costs and sending statements to customers. If the interest rate is 0.5% per month, what is the present value of eliminating this cost by sending the statements electronically? 5) You have decided to buy perpetuity. The bond makes one payment atition end of every year forever and has an interest rate of 8%. If you initially put $1,000 into the bond, what is the payment every year