Taxi fare standard: 6 yuan for less than 3 kilometers (including 3 kilometers); 1.3 yuan for each additional 1 kilometer for more than 3 kilometers. Mom goes from home to grandma's house. When she gets off the bus, the meter shows 11.85 yuan. How many kilometers is the distance between mother's house and grandma's house?
出租车收费标准：3千米以下(含3千米)收6元；3千米以上，每增加1千米收费1.3元．妈妈从家到外婆家，下车时计价表显示11.85元，妈妈家离外婆家大约多少千米？
<gadget id="calculator">11.85 - 6</gadget>
<output>5.85</output>

<gadget id="calculator">5.85 / 1.3</gadget>
<output>4.5</output>

<gadget id="calculator">4.5 + 3</gadget>
<output>7.5</output>

<result>7.5</result>