The apprentice processed 72 parts in 9 hours, and the master processed 15 more parts per hour than the apprentice on average. How many parts does the master process per hour?
徒弟9小时加工零件72个，师傅平均每小时比徒弟多加工零件15个．师傅每小时加工多少个零件？
<gadget id="calculator">72 / 9</gadget>
<output>8</output>

<gadget id="calculator">8 + 15</gadget>
<output>23</output>

<result>23</result>