Xiaohong, Xiaodong and Xiaoli spent the same amount of money to buy exercise books. After buying, Xiaohong and Xiaodong each took 6 more books than Xiaoli, so they each paid Xiaoli 0.6 yuan. How much is the price of each exercise book.
小红、小东和小丽三个同学拿同样多的钱去买练习本，买完后，小红和小东比小丽各多拿了6本，因此二人各还小丽0.6元．每本练习本的价钱是多少元．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

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

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

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

<result>0.3</result>