If Stock's, required rate of return, calculated using CAPM is $15\%,$ stock's beta is $2,$ and the return on the market is twice the risk$-$free rate, then The risk$-$free rate is $5\%$ The risk$-$free rate is $7\%$ The risk$-$free rate is $3\mathrm{.}5\%$ The return on the market is $8\%$