請教財工問題 - 金融分析師

這題試著以r_m,r_f,r_A求解,卻一直卡住
想請強者好心幫忙解答一下～感激不盡！！


Assume capital markets are perfect
(no corporate income taxes or other imperfections)
and the Miller and Modigliani propositions hold.
At a debt-to-equity ratio of 25%, a firm has a debt beta of 10% and
an equity beta of 121.25%. The firm issues more debt and repurchases
equity to bring its debt-to-equity ratio to 50%, where its debt beta
is 17.5%.

Question 1: Beta of assets in perfect capital markets
What is the firm’s beta of assets at the debt-to-equity ratio of 50%?

Question 2: Beta of equity in perfect capital markets
What is the firm’s beta of equity at the debt-to-equity ratio of 50%?

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