you are considering investing in a new gold mine in south africa. gold in south africa is buried very deep, so the mine will require an initial investment of $290 million. once this investment is made, he mine is expected to produce revenues of $30 million per year for the next 20 years. it will cost $12.5 million per year to operate the mine. after 20 years, the gold will be depleted. the mine must then be stabilized on an ongoing basis, which will cost $4.5 million per year in perpetuity. calculate the irr of this investment or state whether no positive irr exists, with justification.