XYZ Corp. has a debt to equity ratio of $0\mathrm{.}5,$ the firm's equity cost of capital is $10\%$ and the firm has risk$-$free debt with an interest rate of $5\%.$ In perfect capital markets what will be the cost of capital of the firm's operating assets if XYZ changes its debt to equity ratio to $0\mathrm{.}75?$ Enter your answer as a percent without the $"\%."$ Round your final answer to two decimals.