In May of a certain year, cloudy days are less than sunny days (1/3), rainy days are less than sunny days (3/5), how many days are sunny in this month.
某年五月份中，阴天比晴天少(1/3)，雨天比晴天少(3/5)，这个月有多少天是晴天．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (1/3) - (3/5)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 + 1 + (1/15)</gadget>
<output>31/15 = around 2.066667</output>

<gadget id="calculator">31 / (31/15)</gadget>
<output>15</output>

<result>15</result>