The three classes of the fourth grade participated in the sports meeting. In the sports meeting, three competitions were held in the high jump, long jump and 100-meter race. It is known that Class 1 has the least number of people entering the top 3, Class 2 has twice as many people entering the top 3 as Class 1, and the total scores of these two classes are equal, and they are tied for the first place in the grade group. How much did Class 3 get? point.
四年级三个班参加运动会，运动会上举行跳高、跳远和百米赛跑三项比赛，各取前3名，第一名得5分，第二名得3分，第三名得1分．已知1班进入前3名的人数最少，2班进入前3名人数是1班的2倍，而这两个班所得总分相等，且是年级组的并列第1名，3班得了多少分．
<gadget id="calculator">1 + 3 + 5</gadget>
<output>9</output>

<gadget id="calculator">3 * 9</gadget>
<output>27</output>

<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">10 + 10</gadget>
<output>20</output>

<gadget id="calculator">27 - 20</gadget>
<output>7</output>

<result>7</result>