The starting price of a taxi is 6 yuan (within 3km), and the fare is 1.2 yuan/km for a distance exceeding 3km. Dongdong pays a total of 20.4 yuan for taking a taxi from home to the exhibition hall. How many kilometers is it from Dongdong’s home to the exhibition hall?
出租车起步价6元(3km以内)，超过3km的路程按1.2元/km付费，冬冬坐出租车从家里到展览馆共付20.4元，冬冬家到展览馆大约有多少千米？
<gadget id="calculator">20.4 - 6</gadget>
<output>14.4</output>

<gadget id="calculator">14.4 / 1.2</gadget>
<output>12</output>

<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<result>15</result>