There are wild fruits that monkeys like to eat in the forest. 23 monkeys can eat all of them within 9 weeks, and 21 monkeys can eat all of them within 12 weeks. If you want to eat all of the wild fruits in 4 weeks, how many monkeys need to eat them together ( Assuming the wild fruit grows at a constant rate)
林子里有猴子喜欢吃的野果，23只猴子可在9周内吃光，21只猴子可在12周内吃光，问如果要4周吃光野果，则需有多少只猴子一起吃(假定野果生长的速度不变)
<gadget id="calculator">23 * 9</gadget>
<output>207</output>

<gadget id="calculator">21 * 12</gadget>
<output>252</output>

<gadget id="calculator">252 - 207</gadget>
<output>45</output>

<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">45 / 3</gadget>
<output>15</output>

<gadget id="calculator">15 * 9</gadget>
<output>135</output>

<gadget id="calculator">207 - 135</gadget>
<output>72</output>

<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<gadget id="calculator">18 + 15</gadget>
<output>33</output>

<result>33</result>