During the National Day, colorful flags are planted in the school playground, arranged in the order of 3 red, 2 yellow, and 1 green. A total of 60 red flags are planted, and how many yellow flags are planted.
国庆节期间，学校操场插彩旗，按3红、2黄、1绿的顺序排列，共插60面红旗，插黄旗多少面．
<gadget id="calculator">60 / 3</gadget>
<output>20</output>

<gadget id="calculator">2 * 20</gadget>
<output>40</output>

<result>40</result>