From Xiaohua's home to the school, there are uphill roads and small slope roads, and there is no flat road, a total of 2.4 kilometers. Xiaohua has to walk 1.1 hours to school every day. It is known that Xiaohua walks 2 kilometers per hour when going uphill, and 3 kilometers per hour when going downhill. So how many hours does Xiaohua have to walk home from school?
小华家到学校有上坡路和小坡路，没有平路，共2.4千米．小华每天上学要走1.1小时．已知小华上坡时每小时走2千米，下坡时每小时走3千米．那么小华放学回家要走多少小时．
<gadget id="calculator">2.4 / 2</gadget>
<output>1.2</output>

<gadget id="calculator">2.4 / 3</gadget>
<output>0.8</output>

<gadget id="calculator">0.8 - 1.1</gadget>
<output>-0.3</output>

<gadget id="calculator">1.2 + (-0.3)</gadget>
<output>0.9</output>

<result>0.9</result>