Mr. Li took a taxi to play in a park 15 kilometers away from his home in Fuzhou. It was 5 yuan within 3 kilometers, and 1.4 yuan for every 1 kilometer. How much should Mr. Li pay?
李老师在抚州打的到距家15千米的公园玩，3千米以内5元，每超过1千米1.4元，李老师应付多少元？
<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<gadget id="calculator">12 * 1.4</gadget>
<output>16.8</output>

<gadget id="calculator">5 + 16.8</gadget>
<output>21.8</output>

<result>21.8</result>