The school arranges dormitories for freshmen. If there are 9 people in one room (just full) than 12 people in one room (also just full), two more dormitories will be used. How many newborns are there in total?
学校给新生安排宿舍，如果按9人一间安排(刚好住满)要比按12人一间安排(也刚好住满)多用两间宿舍．一共有新生多少人．
<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">9 * (2/3)</gadget>
<output>6</output>

<gadget id="calculator">12 * 6</gadget>
<output>72</output>

<result>72</result>