Xiaohong and Xiaoliang are playing a game of "rock, paper, scissors". Agreement: In each round, if you win, you will get 3 points, if you lose, you will deduct 2 points, and each round will be divided into winners and losers. Before the game starts, the two players each have 20 points. After playing 10 rounds, Xiaohong's score is 40 points, then how many rounds Xiaohong has won.
小红和小亮玩"石头剪刀布"的游戏．约定：在每个回合中，如果赢了就得3分，输了就扣2分，每个回合都分出胜负．游戏开始前，两人各有20分．玩了10个回合后，小红的得分是40分，则小红赢了多少个回合．
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">40 - 20</gadget>
<output>20</output>

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

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">10 / 5</gadget>
<output>2</output>

<gadget id="calculator">10 - 2</gadget>
<output>8</output>

<result>8</result>