It took Li Ming 10 minutes to go from home to school, and 15 minutes to return. What is the speed of going back?
李明从家到学校用了10分钟，回来时用了15分钟，去时速度是回来速度的多少
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) / (1/15)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>