求此两个问题的解答

1. 求 The promised yield to maturity =与the expected yield之间的差别是什么。

2.求下面此题答案B 中0.8130如何算来的

Given the following transition matrix, what is the probability that a bond, currently rated A will be rated B in one-year and the probability that it will rated B in two years

(a) one-year probability is 0.06, two-year probability is 0.0910

(b) one-year probability is 0.06, two-year probability is 0.8130

(c) one-year probability is 0.05, two-year probability is 0.8130

(d) one-year probability is 0.05, two-year probability is 0.0910

(e) none of the above

Answer: B