It takes 30 hours for the master to process a batch of parts alone. If the apprentice processes the parts for 9 hours first, and the rest is processed by the master, it will take 24 hours. How many hours will the apprentice process alone?
加工一批零件，师傅单独加工要30小时完成，如果徒弟先加工了9小时，其余的再由师傅加工，还要24小时，那么徒弟单独加工要多少小时完成？
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/30) * 24</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / 9</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">1 / (1/45)</gadget>
<output>45</output>

<result>45</result>