For a particular firm, purchasers of common stock require on 11% rate of return, mortgage bonds are sold at 8% internal rate, and bank loans are available at interest rate of 10%. Capital structure is given below: Rate of Return Annual Amount Php 40 million Bank Loan 10% Php4 million Php 60 million Mortgage Bonds 8% Php 4.8 million Php100 million Common Stock and 11% Php 11 million Retained Earnings Php 200 million Php 19.8 million a. Find before tax cost of capital. b. Find after tax cost of capital if tax rate is 34%