On weekends, my father and mother took Yangyang to play in an amusement park 12 kilometers away from home. They took a taxi from their doorstep to the amusement park. The rice part is charged at an average of 1.5 yuan per kilometer. When we arrive at the amusement park, how much should Dad give the taxi driver?
周末，爸爸和妈妈带洋洋去离家12千米远的游乐园玩，他们从家门口坐出租车去游乐园，根据规定，出租车起步价为5元(3千米以内)，超过3千米部分，平均每千米按1.5元收取，到了游乐园，爸爸应给出租车司机多少元呢？
<gadget id="calculator">12 - 3</gadget>
<output>9</output>

<gadget id="calculator">9 * 1.5</gadget>
<output>13.5</output>

<gadget id="calculator">5 + 13.5</gadget>
<output>18.5</output>

<result>18.5</result>