Can someone please help me on these two questions? Thank you so much

Turnbull Co. has a target capital structure of 45% debt, 4% preferred stock, and 51% common equity. It has a before-tax cost of debt of 11.1%, and its cost of preferred stock is 12.2%. If Turnbull can raise all of its equity capital from retained earnings, its cost of common equity will be 14.7%. However, if it is necessary to raise new common equity, it will carry a cost of 16.8%. If its current tax rate is 40%, how much higher will Tumbull's weighted average cost of capita (WACC) be if it has to raise additional common equity capital by issuing new common stock instead of rasing the funds through retained earnings