Master Zhang worked for 3 hours in the morning and made a total of 39 parts. If the work efficiency remains the same, the working time in the afternoon is 1 hour less than that in the morning, how many same parts can he make in the afternoon.
张师傅上午工作3小时，共做了39个零件．如果工作效率不变，下午工作时间比上午增加1倍少1小时，他下午可以做多少个同样的零件．
<gadget id="calculator">39 / 3</gadget>
<output>13</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">13 * 5</gadget>
<output>65</output>

<result>65</result>