Gwangwa Gold, a South African gold producer, has as its primary asset a mine which isShown on the balance sheet with a value of R100 million. An analyst estimates the marketValue of this mine to be 90% of book value. The company's balance sheet shows other assets of R20 million and liabilities of R40 million, and the analyst feels that the book value of these items reflects their market values. Using the asset-based valuation approach, what should the analyst estimate the value of the company to be?