There are two piles of cement, pile A has 280 tons and pile B has 245 tons. 18 tons are transported from pile A and 11 tons from pile B every day. How many days later are the two piles left with equal weight?
两堆水泥，甲堆有280吨，乙堆有245吨．每天从甲堆运走18吨，从乙堆运走11吨．几天后两堆剩下的重量相等？
<gadget id="calculator">280 - 245</gadget>
<output>35</output>

<gadget id="calculator">18 - 11</gadget>
<output>7</output>

<gadget id="calculator">35 / 7</gadget>
<output>5</output>

<result>5</result>