A ticket for the World Cup football game is 150 yuan. After the price reduction, the audience increases by half and the income increases by one-fifth. How much is the price of a ticket reduced?
世界杯足球比赛门票150元一张，降价后观众增加了一半，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">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">(6/5) / (3/2)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">150 * (4/5)</gadget>
<output>120</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<result>30</result>