Between 12:00 midnight and 12:00 noon of a day, how many times the hour and minute hands on the clock face are at right angles.
一天的深夜12：00到中午12：00之间，钟面上的时针与分针有多少次成直角．
<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">60 / (11/12)</gadget>
<output>720/11 = around 65.454545</output>

<gadget id="calculator">720 / (720/11)</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<result>22</result>