It turned out that Mr. Zhang rode an electric bike to work, and at a speed of 320 m/min, it took 4 minutes from home to school. Now for fitness, she walks to work instead, walking at a speed of 64 m/min, how many minutes does it take to get from home to school?
原来张老师骑电动车上班，以320米/分的速度，从家到学校需要4分钟．现在为了健身，她改为步行上班，以64米/分的速度步行，从家到学校需要几分钟？
<gadget id="calculator">4 / 64</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">320 * (1/16)</gadget>
<output>20</output>

<result>20</result>