masters and 4 apprentices can complete a batch of parts in one day (3/10), and 8 masters and 10 apprentices can complete this batch of parts in one day. If all these parts need to be finished by the apprentice in one day, then how many apprentices should be needed.
2个师傅和4个徒弟一天可以做完一批零件的(3/10)，8个师傅和10个徒弟一天就能把这批零件做完．若这批零件全部要徒弟一天做完，那么，应需徒弟多少人．
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) * 4</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) - 1</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">16 - 10</gadget>
<output>6</output>

<gadget id="calculator">(1/5) / 6</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / (1/30)</gadget>
<output>30</output>

<result>30</result>