Each sapling is 30 yuan, buy 10 get 5 free, buy 30 at a time, how much is each sapling actually?
每棵树苗30元，买10棵送5棵，一次买30棵，实际每棵多少钱？
<gadget id="calculator">20 / 30</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">30 * (2/3)</gadget>
<output>20</output>

<result>20</result>