A pair of gears mesh with each other. The large gear has 40 teeth and the small gear has 30 teeth. If the large gear rotates 120 revolutions per minute, how many revolutions should the small gear rotate per minute? (Solve with ratio)
一对互相咬合的齿轮，大齿轮有40个齿，小齿轮有30个齿，如果大齿轮每分钟转动120圈，小齿轮每分钟应该转动多少圈？(用比例解)
<gadget id="calculator">40 / 30</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">120 * (4/3)</gadget>
<output>160</output>

<result>160</result>