Xinhua Bookstore is a kind of dictionary, which is priced at 30% profit. "61" Children's Day is going to have a 20% discount promotion, so that each book can get a profit of 2.4 yuan. How much is the purchase price of each dictionary?
新华书店一种辞典，按30%的利润定价．"六一"儿童节准备搞八折促销，这样每本还可以获得利润2.4元．每本辞典的进价是多少元？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 + (3/10)</gadget>
<output>13/10 = around 1.3</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(13/10) * (4/5)</gadget>
<output>26/25 = around 1.04</output>

<gadget id="calculator">(26/25) - 1</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">2.4 / (1/25)</gadget>
<output>60</output>

<result>60</result>