The telephone penetration rate in Xingfu Community is 80%. After investigation, there are 28 households in this community without telephones. How many households are there in Xingfu Community?
幸福小区电话普及率是80%，经调查，该小区有28户未安装电话，幸福小区共多少户．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">28 / (1/5)</gadget>
<output>140</output>

<result>140</result>