Xinhua Bookstore buys a batch of books, and if they sell them at the price, they can make a profit of 1.2 yuan per book. Now sell at a reduced price, and the sales volume has doubled, and the profit has increased by 50%. How much will the sales of each book be reduced?
新华书店购进一批图书，如果按定价出售，每本获利1.2元．现在降价销售，结果销售量增加了一倍，利润增加50%，每本书的销售降低多少元？
<gadget id="calculator">1.2 * 2</gadget>
<output>2.4</output>

<gadget id="calculator">50 / 100</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">1.2 * (3/2)</gadget>
<output>1.8</output>

<gadget id="calculator">2.4 - 1.8</gadget>
<output>0.6</output>

<gadget id="calculator">0.6 / 2</gadget>
<output>0.3</output>

<result>0.3</result>