Two people, A and B, are overhauling a 1000m long gas pipeline. A overhauls 100m per hour, and B overhauls 150m per hour. Now they cooperate, how long will it take to complete?
甲、乙两人检修一条长1000m的煤气管道，甲每小时检修100m，乙每小时检修150m，现在两人合作，需要多长时间完成？
<gadget id="calculator">100 + 150</gadget>
<output>250</output>

<gadget id="calculator">1_000 / 250</gadget>
<output>4</output>

<result>4</result>