A pair of meshing gears, the driving wheel has 25 teeth, turns 100 revolutions per minute, and the driven wheel has 20 teeth, how many revolutions per minute?
一对互相咬合的齿轮，主动轮有25个齿，每分钟转100圈，从动轮有20个齿，每分钟转多少圈？
<gadget id="calculator">25 * 100</gadget>
<output>2_500</output>

<gadget id="calculator">2_500 / 20</gadget>
<output>125</output>

<result>125</result>