In q 14.9 they have used y0,5 and F0,5,5 . I understood why they used this but the question is couldn't we use y0,5 and y5,5? If not, then why not?
Based on the info given in the question, no! You are asked to discount from time 10 back to time 0, hence you must use the current term structure of interest rates, ie those that apply at time 0, y0,5 and F0,5,5
