The financial assistant of a geared company has prepared the following calculation of the company's...

The assistant has discounted free cash flows to all investors at the WACC (10%). That gives the value of the business (enterprise value), not directly the value of equity.

For a geared company:

If you discount free cash flows to the firm (all investors) at the WACC, you obtain the total value of the firm (V).

To get equity value (E), you must then subtract the market value of debt (D):

E=V−DE = V - DE=V−D

Here, the company has a $6m 7% undated bond trading at par, so the market value of debt is $6m. That amount has not been deducted.

The other options are not errors:

The perpetuity discounting using 7.91.102×0.10\frac{7.9}{1.10^2 \times 0.10}1.102×0.107.9​ is correct for a constant cash flow from year 3 onward.

Using WACC (10%) is appropriate for FCFF.

Tax at 20% is already reflected in either the cash flows or the WACC; it is not “missing” as a separate line.

So the specific mistake is failing to deduct the $6m debt value, i.e. option D.