The water level of a barrier lake formed by the Sichuan earthquake will reach the top of the dam after 20 days of measurement. In order to prolong the time to transfer the downstream people, a flood discharge channel was opened to drain the water. What fraction of the water flowing into the lake is the amount of water flowing out? (Write out the solution process)
四川地震形成的一个堰塞湖经过测量20天后水位将达到坝的顶端，为了延长时间转移下游群众，开辟了一个泄洪渠道向外排水，这样可使水位到达坝顶推迟到30天，那么每天泄出水量是流入湖中水量的几分之几？(写出解答过程)
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/20) - (1/30)</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/60) / (1/20)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>