Question

A wheel that has 6 cogs is meshed with a larger wheel of 14 cogs. When the smaller wheel has made 21 revolutions, then the number of revolutions made by the larger wheel is

Options

• 7

• 9

• 14

• 42

Answer 1

9

Explanation:

Let the required number of revolutions made by larger wheel be x, Then more cogs, less revolutions 
(indirect proportion)

∴ 14 : 6 : : 21 : x

`⇒ "x" =(21xx6)/14=9`