There is a vending machine in the company that provides Coke for employees, and there is a special person responsible for replenishing Coke every day, and the amount of Coke replenished is the same every day. If the company has 5 employees, the Coke in the vending machine will be sold out after 30 days; if the company has 6 employees, the Coke in the vending machine will be sold out after 20 days. It is known that each employee buys the same amount of Coke every day. If 4 employees bought it 30 days later, and then recruited 2 new employees, how many days will it take for all the Cokes to be sold out?
公司里有一台自动售货机为员工提供可乐，每天有专人负责补充可乐，且每天补充可乐的数量是相同的．如果公司有5个员工，那么30天后自动售货机内的可乐正好卖完；如果公司有6个员工，那么20天后自动售货机内的可乐正好卖完．已知每个员工每天买的可乐数量也是相同的．如果4个员工买了30天后，又新招入2个员工，那么所有的可乐几天后卖完？
<gadget id="calculator">5 * 30</gadget>
<output>150</output>

<gadget id="calculator">6 * 20</gadget>
<output>120</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<gadget id="calculator">3 * 30</gadget>
<output>90</output>

<gadget id="calculator">150 - 90</gadget>
<output>60</output>

<gadget id="calculator">4 * 30</gadget>
<output>120</output>

<gadget id="calculator">90 - 120</gadget>
<output>-30</output>

<gadget id="calculator">60 + (-30)</gadget>
<output>30</output>

<gadget id="calculator">2 - 3</gadget>
<output>-1</output>

<gadget id="calculator">4 + (-1)</gadget>
<output>3</output>

<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<result>10</result>