Tickets for a certain competition are 100 yuan each. After the price is reduced, the audience will double and the income will increase by half. How much is the price reduction for each ticket.
某次比赛门票每张100元，降价后观众增加1倍，收入增加一半．每张门票降价多少元．
<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">100 * (3/2)</gadget>
<output>150</output>

<gadget id="calculator">150 / 2</gadget>
<output>75</output>

<gadget id="calculator">100 - 75</gadget>
<output>25</output>

<result>25</result>