The starting price of a taxi in a certain city is 5 yuan (within 3 kilometers), and the average price is 2 yuan per kilometer for more than 3 kilometers. Fanfan’s family of three paid a total of 13 yuan for the taxi to his grandfather’s house. Fanfan’s house is far away from his grandfather’s house how far?
某市出租车起步价为5元(3千米以内)，超过3千米，平均每千米2元，凡凡一家三口人乘出租车到爷爷家共付车费13元，凡凡家离爷爷家有多远？
<gadget id="calculator">13 - 5</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<result>7</result>