The ratio of the teeth of two circular gears meshing with each other is 3:4, the small gear has 63 teeth, and how many teeth does the large gear have.
两个相互咬合的圆形齿轮齿数之比是3：4，其中小齿轮有63个齿，大齿轮有多少个齿．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">63 / (3/4)</gadget>
<output>84</output>

<result>84</result>