Two engineering teams, A and B, are repairing the tunnel. They start construction at the same time. After opening, team A is 4 kilometers away from the midpoint. Team A excavates 2.4 kilometers per day, and team B excavates 2.6 kilometers per day. How long is this tunnel in kilometers?
甲乙两个工程队修隧道，它们同时开工，开通后甲队距中点4千米．甲队每天开凿2.4千米，乙队每天开凿2.6千米，这条隧道全长多少千米？
<gadget id="calculator">2.6 - 2.4</gadget>
<output>0.2</output>

<gadget id="calculator">2 / 0.2</gadget>
<output>10</output>

<gadget id="calculator">2.6 + 2.4</gadget>
<output>5</output>

<gadget id="calculator">4 * 10 * 5</gadget>
<output>200</output>

<result>200</result>