Operating Leverage:
Operating leverage refers to the extent to which a firm's operating income changes in response to a change in sales. It measures the sensitivity of operating income to changes in sales. The formula to calculate operating leverage is as follows:

Operating Leverage = Contribution Margin / Operating Income

Financing Leverage:
Financing leverage refers to the extent to which a firm's net income changes in response to a change in operating income. It measures the sensitivity of net income to changes in operating income. The formula to calculate financing leverage is as follows:

Financing Leverage = Operating Income / Net Income

Combined Leverage:
Combined leverage is the product of operating leverage and financing leverage. It measures the overall sensitivity of net income to changes in sales. The formula to calculate combined leverage is as follows:

Combined Leverage = Operating Leverage * Financing Leverage

Given Information:
- Sales: Rupees 10 lakh
- Variable Cost: Rupees 7 lakh
- Fixed Cost: Rupees 200000
- Debentures: Rupees 500000 at 10% interest rate

Calculating Operating Leverage:
Contribution Margin = Sales - Variable Cost = 10 lakh - 7 lakh = 3 lakh
Operating Income = Sales - Variable Cost - Fixed Cost = 10 lakh - 7 lakh - 2 lakh = 1 lakh

Operating Leverage = Contribution Margin / Operating Income = 3 lakh / 1 lakh = 3

Calculating Financing Leverage:
Interest Expense = Debentures * Interest Rate = 500000 * 10% = 50000
Net Income = Operating Income - Interest Expense = 1 lakh - 50000 = 50000

Financing Leverage = Operating Income / Net Income = 1 lakh / 50000 = 2

Calculating Combined Leverage:
Combined Leverage = Operating Leverage * Financing Leverage = 3 * 2 = 6

Doubling Earnings Before Interest and Tax (EBIT):
To double the EBIT, we need to find the increase in sales required. Let's assume the current EBIT is X.

EBIT = Sales - Variable Cost - Fixed Cost
X = 10 lakh - 7 lakh - 2 lakh
X = 1 lakh

To double the EBIT, we need to find the new sales amount (Y).

2X = Y - 7 lakh - 2 lakh
2 lakh = Y - 7 lakh - 2 lakh
2 lakh + 7 lakh + 2 lakh = Y
Y = 11 lakh

The firm needs to increase its sales to 11 lakh in order to double its EBIT.

Conclusion:
- The operating leverage of the firm is 3, indicating that a 1% increase in sales will result in a 3% increase in operating income.
- The financing leverage of the firm is 2, indicating that a 1% increase in operating income will result in a 2% increase in net income.
- The combined leverage of the firm is 6, indicating that a 1% increase in sales will result in a 6% increase in net income.
- To double its EBIT, the firm needs to increase its sales from 10 lakh to