Sum $20$: Ingham plc$\text{'}$s capital structure is as follows:

$\backslash$table$[[50$c ordinary shares,$m$],[8\%$ $$1$ preference shares,$6],[12\mathrm{.}5\%$ loan notes $20$X$6,8],[,26]]$

The loan notes are redeemable at nominal value in $20$X$6.$ The current market prices of the company's securities are as follows.

$50$ c ordinary shares $250$ c

$8\%$$$1$ preference shares $92c$

$12\mathrm{.}5\%$ loan notes $20x6$$$100$

The company is paying corporation tax at the rate of $30\%.$ The cost of the company's ordinary equity capital has been estimated at $18\%$ pa$.$ What is the company's weighted average cost of capital for capital investment appraisal purposes?