You were hired as a consultant to Alibaba, whose target capital structure is 40% debt, 30% preferred, and 30% common equity. The interest rate on new debt is 6%, the yield on the preferred is 8%, the cost of retained earnings is 10%, and the tax rate is 20%. The firm will not be issuing any new stock. What is Alibaba's WACC? (submit your answer in percentages, NOT in decimals)