Today is 1 July, 2019. Siobhn has a portfolio which consists of two different types of financial instruments (henceforth referred to as instrument A and instrument B). Siobhn purchased all instruments on 1 July 2011 to create this portfolio, which is composed of 34 units of instrument A and 23 units of instrument B.

• Instrument A is a zero-coupon bond with a face value of $100. This bond matures at par. Its maturity date is 1 January 2029.
• Instrument B is a Treasury bond with a coupon rate of j₂=2.38% p.a. and a face value of $100. This bond matures at par. Its maturity date is 1 January 2022.

Calculate the current duration of Siobhns portfolio using a yield to maturity of j₂=4.29% p.a. Express your answer in terms of years and round your answer to two decimal places.

Answer

a.

6.80 years

b.

7.32 years

c.

5.83 years

d.

6.03 years