The original price of a football match ticket is 40 yuan per ticket. After the price reduction measures are adopted, the audience doubles and the income increases by one-fifth. How much is the price of a ticket reduced?
一场足球赛门票原价为40元一张，采取降价措施后观众增加了一倍，收入增加了五分之一，则一张门票降价多少元．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) / 2</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">40 * (3/5)</gadget>
<output>24</output>

<gadget id="calculator">40 - 24</gadget>
<output>16</output>

<result>16</result>