There are 3 numbers A, B, and C. The sum of A, B, and C is 90. The sum of A, C, and B is 82. The sum of B, C, and C is 86. Find the average of A, B, and C. ?
有甲、乙、丙3个数，甲乙两数的和是90，甲丙两数的和是82，乙丙两数的和是86，求：甲、乙、丙三数的平均数是多少？
<gadget id="calculator">90 + 82 + 86</gadget>
<output>258</output>

<gadget id="calculator">258 / 2 / 3</gadget>
<output>43</output>

<result>43</result>