The average of A, B, and C is 86. If A is reduced by 9, what is the average of A, B, and C?
甲、乙、丙的平均数是86，如果甲减少9，那么甲、乙、丙的平均数是多少．
<gadget id="calculator">86 * 3</gadget>
<output>258</output>

<gadget id="calculator">258 - 9</gadget>
<output>249</output>

<gadget id="calculator">249 / 3</gadget>
<output>83</output>

<result>83</result>