A, B, and C each spend 9 yuan to buy exercise books. Since A wants 15 less books than C, and B wants as much as C, each of B and C must give A another 1.5 yuan. How much is the exercise book?
甲乙丙三人各拿出9元钱买练习本，由于甲比丙少要15本，乙与丙要的一样多，因此，乙和丙每人都要再给甲1.5元，问：每本练习本多少钱？
<gadget id="calculator">9 + 1.5</gadget>
<output>10.5</output>

<gadget id="calculator">1.5 * 2</gadget>
<output>3</output>

<gadget id="calculator">9 - 3</gadget>
<output>6</output>

<gadget id="calculator">10.5 - 6</gadget>
<output>4.5</output>

<gadget id="calculator">4.5 / 15</gadget>
<output>0.3</output>

<result>0.3</result>