Xiaofang went to buy a book, paid 50 yuan, and got 26.4 yuan back. Later, the cashier found that she had found an extra 10.3 yuan. How much is the price of this book?
小芳去买书，付了50元，找回了26.4元，后来收银员发现多找了10.3元，这本书价格是多少元？
<gadget id="calculator">50 - 26.4</gadget>
<output>23.6</output>

<gadget id="calculator">23.6 + 10.3</gadget>
<output>33.9</output>

<result>33.9</result>