The gear ratio of the large and small gears is 8:5, the large gear has 40 teeth, how many teeth does the small gear have.
大小两个齿轮的齿数比是8：5，大齿轮有40个齿，小齿轮有多少个齿．
<gadget id="calculator">40 * 5</gadget>
<output>200</output>

<gadget id="calculator">200 / 8</gadget>
<output>25</output>

<result>25</result>