If the average of the three numbers A, B, and C is 7.5, what is the sum of the three numbers A, B, and C?
甲、乙、丙三个数的平均数是7.5，则甲、乙、丙三个数的和是多少．
<gadget id="calculator">7.5 * 3</gadget>
<output>22.5</output>

<result>22.5</result>