Independent solution
How to solve this Duration and Convexity question
Setup
Setup
Place the first block at times zero through 19 and the second, larger block at times 20 through 49.
Model
Model
Duration requires both ordinary present value and a time-weighted present value; the payment scale X will cancel.
Compute
Compute
The two blocks give value factor 78.1729 and time-weighted factor 2,178.3542.
Answer
Answer
Their ratio is 27.87 years, corresponding to choice B.