Rumolt Motors has 41 million shares outstanding with a price of $39 per share. In addition, Rumolt has issued bonds with a total current market value of $1,071 million. Suppose Rumolt's equity cost of capital is 11%, and its debt cost of capital is 6%.

a. What is Rumolt's pretax weighted average cost of capital?

b. If Rumolt's corporate tax rate is 38%, what is its after-tax weighted average cost of capital?