Darby Mining Corporation$$s assets consist of three projects. The Project one$$s asset is $10$

million, project two $20$ million and project three $30$ million. The Betas of three projects

are $1\mathrm{.}5,1\mathrm{.}2$ and $0\mathrm{.}7$ respectively. The risk$-$free rate is $2\%$ per annum, market premium is

$3\%$ annually. Assume the CAPM holds.What is the required rate of return on the whole company?