It is known that the average of the four numbers is 25, now add the fifth number 40, what is the average of the five numbers.
已知四个数的平均数是25，现将第五个数40添进去，则这个五个数的平均数是多少．
<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">100 + 40</gadget>
<output>140</output>

<gadget id="calculator">140 / 5</gadget>
<output>28</output>

<result>28</result>