You are required to make a payment of $6000 in 6 years' time. There are currently only two bonds available in the market. A 3 year, 6\% coupon bond with a Present Value of $980 and Future Value of $1000 and an 8 year pure discount bond with a Future Value of $1000. Determine how many units we need to purchase of each bond if we wish to immunize the liability (Assume the discount rate is 4%)