At 3 o'clock in the afternoon, the minute hand is perpendicular to the hour hand, and it will take at least how many minutes before it becomes vertical again.
下午3点整，分针与时针垂直，至少经过多少分钟才会再次垂直．
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 - (1/12)</gadget>
<output>11/12 = around 0.916667</output>

<gadget id="calculator">30 / (11/12)</gadget>
<output>360/11 = around 32.727273</output>

<result>360/11 = around 32.727273</result>