NI Approach
A companys expected annual net operating
  income(EBIT) is Rs.50,000. The company has
  Rs.2,00,000, 10% debentures. The equity
  capitalization rate(ke) of the company is
  12.5%.What is the Market value of the firm?
 What is the overall cost of capital?
 Market value of firm = Rs. 4,40,000
 Overall Capitalization Rate = 11.36%
 Now let us see what is the effect on firm value
  and cost of capital if the firm increases the
  value of debenture by Rs.100,000 and reduces
  the equivalent amount of equity
 Market Value of Firm = Rs. 4,60,000
 Overall Capitalization Rate = 10.86%
 Now let us see what is the effect on firm value
  and cost of capital if the firm decreases the
  value of debenture by Rs.100,000 and reduces
  the equivalent amount of equity
 Market Value of Firm = Rs.4,20,000
 Overall capitalization rate = 11.90%
              NOI Approach
 Operating income Rs.50,000; cost of debt 10%
  and outstanding debt Rs.200,000. If the
  overall capitalization rate(overall cost of
  capital) is 12.5%, what would be the total
  value of the firm and equity capitalization
  rate?
 Overall firm value = 4,00,000
 Equity capitalization rate = 15%
 If amount of debt increases by Rs.100,000 and
  corresponding decease in equity by same
  amount. what would be the total value of the
  firm and equity capitalization rate?
 Overall firm value = 4,00,000
 Equity capitalization rate = 20%
 If amount of debt decreases by Rs.100,000
  and corresponding increase in equity by same
  amount. what would be the total value of the
  firm and equity capitalization rate?
 Overall firm value = 4,00,000
 Equity capitalization rate = 13.33%