This question is not cumulative

$[8$ marks$]$

$($a$)$ Ayden Inc.$\text{'}$s common stock has paid a dividend of $$3\mathrm{.}5$ per share per year for the last $12$ years. Stock analysts expect it to continue to pay at that amount for the foreseeable future. The current required rate of return for the stock is $11\%.$ What is the current price of the stock?

$($b$)$ The Starr Co$.$ just paid a dividend of $$1\mathrm{.}90$ per share on its stock. The dividends are expected to grow at a constant rate of $5$ percent per year, indefinitely. If investors require a $12$ percent return on the stock, what is the current price? What will the price be in three years? in $15$ years?