round to the nearest cent please, will rate positive

Perpetuities. The Canadian Government has once again decided to issue a consol (a bond with a never-ending interest payment and no maturity date). The bond will pay $70 in interest each year (at the end of the year), but it will never return the principal. The current discount rate for Canadian government bonds is 7%. What should this consol bond sell for in the market? What if the interest rate should fall to 6%? Rise to 8%? Why does the price go up when interest rates fall? Why does the price go down when interest rates rise