At about 7:49 on April 14, 2010, an earthquake of magnitude 7.1 occurred in Yushu County, Yushu Tibetan Autonomous Prefecture, Qinghai Province, and the people of the whole country actively supported it. The 30 students in Xiaoxiao's class donated an average of 15.5 yuan, plus the donation from the class teacher Mr. Liu, the average donation was 24.5 yuan. Please do the math, how much did Teacher Liu donate?
2010年4月14日7时49分许，青海省玉树藏族自治州玉树县发生7.1级地震，全国人民积极支援．笑笑所在的班级30名同学平均捐款15.5元，加上班主任刘老师的捐款，平均捐款24.5元．请你算一算，刘老师捐了多少钱？
<gadget id="calculator">30 + 1</gadget>
<output>31</output>

<gadget id="calculator">24.5 * 31</gadget>
<output>759.5</output>

<gadget id="calculator">15.5 * 30</gadget>
<output>465</output>

<gadget id="calculator">759.5 - 465</gadget>
<output>294.5</output>

<result>294.5</result>