Teacher Li bought 3 identical pens, paid 50 yuan, and got 24.5 yuan back. How much is each pen?
李老师买了3支同样的钢笔，付了50元钱，找回24.5元，每支钢笔多少元？
<gadget id="calculator">50 - 24.5</gadget>
<output>25.5</output>

<gadget id="calculator">25.5 / 3</gadget>
<output>8.5</output>

<result>8.5</result>