Xiao Ming (2/5) walks 4 kilometers in an hour, ask "How many hours does it take her to walk 1 kilometer?" What is the formula?
小明(2/5)小时走4千米，求"她走1千米需用多少小时？"列式是多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / 4</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>