In September of a certain year, there are 20 sunny days, fewer (4/5) rainy days than sunny days, and more (1/2) cloudy days than rainy days. How many cloudy days are there in this month?
某年9月份晴天有20天，雨天的天数比晴天少(4/5)，阴天的天数比雨天多(1/2)．这个月阴天有多少天？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">20 * (1/5) * (3/2)</gadget>
<output>6</output>

<result>6</result>