Sam Ltd has just commenced operations with the following capital structure:

Additional information:

1. The debentures with ten years to maturity and a $100 par value pay a semi-annual coupon rate of 8% per annum, and were issued at a price of $97.00 each.
2. The term of the mortgage loan is twenty years and the monthly repayment is $12,000 so that the loan (with interest) will be fully repaid at maturity.
3. The new preference shares have a 9% annual dividend with a $5.00 par value were sold at $4.80 per share. In addition, flotation costs of $0.10 per share had to be paid.
4. Due to popular demand for the companys ordinary shares, they traded at $2.20 each immediately after the new issue.
5. The companys prospectus contains estimates that it will earn $500,000 in the first year and will pay dividends of 20 cents per share. Brokers anticipate that dividends will grow at 5% per annum indefinitely.
6. The company income tax rate is 30 cents in the dollar.

You are required to calculate the after-tax weighted average cost of capital for Sam Ltd.