A wheel that has 6 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:	Choose the correct answer:
A) 9
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)   21:6::21:x =&gt; 21 * x = 21 * 6   =&gt; x = (21 * 6)/21   =&gt; x = 6   Answer : 6
<result>C</result>
A wheel that has 6 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: