Xiao Ming bought a schoolbag and a pencil case, and the total cost was 33.8 yuan, and a pencil case was 10.5 yuan. How much is a schoolbag?
小明买了一个书包和文具盒，一共用去了33.8元，一个文具盒10.5元，一个书包多少元？
<gadget id="calculator">33.8 - 10.5</gadget>
<output>23.3</output>

<result>23.3</result>