Li Ming bought a book and a pen. The price of the book is 12 yuan, and the price of the book is just 3/4 of that of the pen. How much is a pen?
李明买了一本书和一支钢笔，书的价格是12元，书的价格刚好是钢笔的(3/4)，一支钢笔多少元？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">12 / (3/4)</gadget>
<output>16</output>

<result>16</result>