The ratio of the number of people in the first workshop to the second workshop of a factory is 9:10, and the ratio of the number of people in the second workshop to the number of the third workshop is 5:7. It is known that there are 99 people in the three workshops. How many people are there in the second workshop than in the third workshop?
某厂一车间与二车间的人数比是9：10，二车间的人数与三车间的人数比是5：7，已知三个车间共99人，求二车间比三车间少多少人？
<gadget id="calculator">9 + 10 + 14</gadget>
<output>33</output>

<gadget id="calculator">99 / 33</gadget>
<output>3</output>

<gadget id="calculator">3 * 14</gadget>
<output>42</output>

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

<gadget id="calculator">42 - 30</gadget>
<output>12</output>

<result>12</result>