The Beta Corporation has an optimal debt ratio of $40$ percent. Its cost of equity capital is $12$ percent and its before$-$tax borrowing rate is $6$ percent. Given a marginal tax rate of $35$ percent.

a$.$ Calculate the weighted$-$average cost of capital. $($Do not round intermediate calculations. Round your answer as a percent rounded to $2$ decimal places.$)$

Weighted$-$average cost of capital

b$.$ Calculate the cost of equity for an equivalent all$-$equity financed firm. $($Do not round intermediate calculations. Round your answer as a percent rounded to $2$ decimal places.$)$

Cost of equity