There is a set of gears meshing with each other. The small gear has 30 teeth, which is (1/5) the number of teeth of the large gear. How many teeth does the big gear have?
有一组互相咬合的齿轮，小齿轮有30个齿，是大齿轮齿数的(1/5)．大齿轮有多少齿？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 / (1/5)</gadget>
<output>150</output>

<result>150</result>