Answer: 
The company’s target debt−equity ratio is :
Debt = 33 %
Equity = 67 %
Step-by-step explanation:
The Weighted Average Cost of Capital is the Cost of all permanent sources of finance pooled together.
WACC = ke × E/V + kd × D/E
Where,
ke = cost of equity
 = 13%
E/V = Market Weight of Equity
 = a
kd = cost of debt
 = interest × ( 1 - tax rate)
 = 8.5 % × (1 - 0.35)
 = 5.525 %
D/E = Market Weight of Debt
 = 1 - a
WACC = 13% × a + 5.525 % (1- a)
Solving this equation for a we get:
a = 0.67
Thus 
Weight of Equity =0.67 or 67 %
Weight of Debt = 0.33 or 33 %