Portfolio A consists of a one-year zero-coupon bond with a face value of $2,000 and a 10-year zero-coupon bond with a face value of $7,000. The current yield on all bonds is 10% per annum.

Calculate the duration of Portfolio A.

Calculate the percentage change in the values of the portfolio for a 0.1% per annum increase in yield.

What is the percentage change in the value of the portfolio for a 4% per annum increase in yield?