Independent solution
How to solve this Portfolio Duration under a Common Yield question
Setup
Setup
Because the coupon bond sells at par, its annual effective yield equals its 6% coupon rate.
Model
Model
Compute Bond A's price-weighted timing at this yield.
Compute
Compute
Price the two zeroes and use their maturities as durations.
Answer
Answer
Market-value weighting gives 7.4261 years, choice B.