The school held a painting competition for grades five and six. There were 14 participants in the fifth grade and 21 participants in the sixth grade. Those who participated (4/7) were winners. How many people won the prizes?
学校举办五六年级的绘画比赛，五年级有14人参加，六年级有21人参加，参赛的(4/7)是获奖者，获奖的有多少人？
<gadget id="calculator">14 + 21</gadget>
<output>35</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">35 * (4/7)</gadget>
<output>20</output>

<result>20</result>