The issue with the question, is that growth rate is $5\mathrm{.}3333\%$ not $12\%$

The 'constant growth model' is:

Stock price$=$ Dividend$/$ Required Rate$-$ Dividend Growth Rate

$\{36=(2\mathrm{.}4)/(\mathrm{.}12-$GR$)\}(\mathrm{.}12-$GR$)$

$4\mathrm{.}32-36$GR$=2\mathrm{.}4$

GR$=5\mathrm{.}333...$