A ticket for a football game is 15 yuan. After the price is reduced, the audience increases by half, and the income increases (1/5). How much is the price of a ticket reduced?
足球赛门票15元一张，降价后观众增加一半，收入增加(1/5)，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">15 * (1/5)</gadget>
<output>3</output>

<gadget id="calculator">15 + 3</gadget>
<output>18</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">18 / (3/2)</gadget>
<output>12</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<result>3</result>