Two engineering teams jointly build a tunnel and excavate from both sides at the same time. Team A builds 50 meters per day. Team B's tunnel is 10 meters shorter than that of Team A, and it will be completed in 8 days. How long is this tunnel?
两个工程队合修一条隧道，同时从两侧开凿，甲队每天修50米．乙队修的比甲队的2倍少10米，8天后修通，这条隧道有多长？
<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">100 - 10</gadget>
<output>90</output>

<gadget id="calculator">50 + 90</gadget>
<output>140</output>

<gadget id="calculator">140 * 8</gadget>
<output>1_120</output>

<result>1_120</result>