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 mad by the larger wheel is:

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 mad by the larger wheel is: Correct Answer 9

Let the required number of revolutions made by larger wheel be x.

 

Then, More cogs, Less revolutions (Indirect Proportion)

 

  14 : 6 :: 21 : x => 14 x x = 6 x 21

 

x=6*21/14  =>  x=9

Related Questions