The railway engineers built a railway, and 90 kilometers have been repaired, which is 10 kilometers more than twice the remaining one. How many kilometers are left to be repaired?
铁道工程兵修建一条铁路，已经修好了90千米，比剩下的2倍还多10千米，还剩下多少千米没修？
<gadget id="calculator">90 - 10</gadget>
<output>80</output>

<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<result>40</result>