Xiaoqiang travels 6 kilometers per hour from his home to the supermarket, and 9 kilometers per hour when he comes back. It takes 1 hour to go back and forth. How many kilometers away is Xiaoqiang's home from the supermarket?
小强从家到超市，去时每小时行6千米，回来时每小时行9千米，来回共用1小时，小强家距超市多少千米？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/6) + (1/9)</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">1 / (5/18)</gadget>
<output>18/5 = around 3.6</output>

<result>18/5 = around 3.6</result>