To celebrate "June 1st", the school dance team purchased several colored ribbons of red, yellow and blue, 20% of which are red, ((x)/6) is yellow, and the remaining 81 are blue of. How many ribbons did the school buy in total?
为庆"六•一"，学校舞蹈队购买了红、黄、蓝三种颜色的彩带若干根，其中20%是红色的，((x)/6)是黄色的，其余81根是蓝色的．学校三种彩带共买了多少根．
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">24 - 15</gadget>
<output>9</output>

<gadget id="calculator">2_430 / 9</gadget>
<output>270</output>

<result>270</result>