A pool can store 63 tons of water, and the ratio of the discharged water to the total capacity is 3:7. How many tons of water are left?
一个水池能蓄水63吨，已经排出的和总容量的比是3：7，还剩下多少吨水？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">63 * (3/7)</gadget>
<output>27</output>

<gadget id="calculator">63 - 27</gadget>
<output>36</output>

<result>36</result>