The average of six numbers is 24, and the average after adding one number is 25. What is the added number?
六个数的平均数是24，加上一个数后的平均数是25，加上的这个数是多少．
<gadget id="calculator">25 * 7</gadget>
<output>175</output>

<gadget id="calculator">24 * 6</gadget>
<output>144</output>

<gadget id="calculator">175 - 144</gadget>
<output>31</output>

<result>31</result>