A company is financed entirely by common stock and has a cost of equity of 12.5%. Now the firm decides to repurchase one-fourth of its shares and substitute an equal value of debt. The debt is risk-free, with an interest rate of 6.5%. The company is exempt from corporate income taxes. Assume MM in its pure form applies.

Calculate the overall cost of capital (WACC), expressed as a percent to one decimal (XX.X)%