A firm with return on equity $20\%$ and beta $0\mathrm{.}5$ just distributed all its earnings $($ $$20$ per share$)$ as dividends. The expected market return is $15\%$ and the risk$-$free rate is $5\%.$ The firm plans to retain $25\%$ of its earnings every year in the future for reinvestment.

What is the price of the stock?

a$.$ $$315$