The average of the two numbers A and B is 75, and the number C is 90. What is the average of these three numbers?
甲、乙两个数的平均数是75，丙数是90，这三个数的平均数是多少．
<gadget id="calculator">75 * 2</gadget>
<output>150</output>

<gadget id="calculator">150 + 90</gadget>
<output>240</output>

<gadget id="calculator">240 / 3</gadget>
<output>80</output>

<result>80</result>