Answer:
13%
Step-by-step explanation:
the new cost of equity = old cost of equity + [(debt / equity) x (old cost of equity - cost of debt)]
the new cost of equity = 12%+ [(20 / 80) x (12% - 8%)] = 12% + 1% = 13%
Since we are in the MM world, taxes do not exist, therefore they are not included in the equation.