Xiao Ming participated in the children's quiz to answer. The known rush answer rule is: each contestant starts to count points from 100 points, 10 points are added for a correct answer, and 5 points are deducted for a wrong answer. Xiao Ming answered 15 questions and got 205 points. How many questions did he get right?
小明参加少儿智力竞赛抢答．已知抢答规则是：每个参赛者从100分开始算分，答对一题加10分，答错一题扣5分．小明抢答了15题，得205分．他答对了多少题？
<gadget id="calculator">15 * 10</gadget>
<output>150</output>

<gadget id="calculator">150 - 205</gadget>
<output>-55</output>

<gadget id="calculator">100 + (-55)</gadget>
<output>45</output>

<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<gadget id="calculator">45 / 15</gadget>
<output>3</output>

<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<result>12</result>