A wheel that has 3 cogs is meshed with a larger wheel of 21 cogs. When the smaller wheel has made 21 revolutions, then the number of revolutions made by the larger wheel is:
Answers:
A) 3
B) 10
C) 6
D) 8
E) 7
Explanation :   Let the required number of revolutions made by larger wheel be x.   Then, More cogs, Less revolutions (Indirect Proportion)   21:3::21:x =&gt; 21 * x = 21 * 3   =&gt; x = (21 * 3)/21   =&gt; x = 3   3nswer : 3
<result>A</result>
A wheel that has 3 cogs is meshed with a larger wheel of 21 cogs. When the smaller wheel has made 21 revolutions, then the number of revolutions made by the larger wheel is: