The distance between A and B is 72 kilometers. A travels 7 kilometers per hour, B travels 5.5 kilometers per hour, and C travels 3.5 kilometers per hour. A and B go from point A to point B, and C goes from point B to point A. The three start at the same time. After a period of time, when A reaches point C on the way, the distance from B and C is exactly the same. How many kilometers did A walk at this time?
A、B两地相距72千米，甲每小时行7千米，乙每小时行5.5千米，丙每小时行3.5千米．甲、乙从A地到B地，丙从B地到A地，三人同时出发，经过一段时间，甲走到途中C地时，离乙和丙的距离恰好相等．此时甲走了多少千米？
<gadget id="calculator">72 + 72</gadget>
<output>144</output>

<gadget id="calculator">7 + 5.5 + 7 + 3.5</gadget>
<output>23</output>

<gadget id="calculator">144 / 23</gadget>
<output>144/23 = around 6.26087</output>

<gadget id="calculator">7 * (144/23)</gadget>
<output>1_008/23 = around 43.826087</output>

<result>1_008/23 = around 43.826087</result>