Pool A has 200 tons of water, and pool B has 150 tons of water. After that, A flows out 15 tons and B flows out 10 tons every hour. After how many hours, the two pools have the same amount of water.
甲水池有水200吨，乙水池有水150吨，以后每小时甲流出15吨，乙流出10吨，多少小时后两个水池水同样多．
<gadget id="calculator">200 - 150</gadget>
<output>50</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">50 / 5</gadget>
<output>10</output>

<result>10</result>