From school to the library, Xiao Ming takes 15 minutes, and Xiao Dong takes 20 minutes. Xiao Ming's speed is Xiao Dong's.
从学校走到图书馆，小明用15分钟，小东用20分钟，小明的速度是小东的多少．
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/15) / (1/20)</gadget>
<output>4/3 = around 1.333333</output>

<result>4/3 = around 1.333333</result>