The market value of XYZ Corporation's common stock is 40 million and the market value of the risk-free debt is 60 million. The beta of the company's common stock is 0.8, and the expected market risk premium is 10%. If the Treasury bill rate is 6%, what is the firm's cost of capital? (Assume no taxes.)

b = 0.8, R_m R_f = 10% or .1, R_f or T-Bill Rate = 6% or .06

R_s = R_f + (R_m R_f) b

R_s = .06 + (.1) 0.8

R_s = .06 + .08 = .14 * 100 = 14%

I got this part, but then it says that rd = 5% and the cost of capital = (0.6) (6) + (0.4) (14) = 9.2%

I would like to know where did rd = 5% come from and the numbers 0.6, 6, 0.4, and 14 come from to arrive at 9.2%