During the "June 1st" period, Xinhua Bookstore held a buy 3 get 1 free event. Xiao Ming bought 12 science fiction books and paid 54 yuan in total. He asked how much the original price of science fiction books was.
"六一"期间，新华书店举行买3赠1活动，小明买了12本科幻书共付54元，问科幻书原价多少元．
<gadget id="calculator">54 / 12</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(9/2) * (4/3)</gadget>
<output>6</output>

<result>6</result>