A wheel that has 12 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 choice:
A) 12  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)   21:12::21:x =&gt; 21 * x = 21 * 12   =&gt; x = (21 * 12)/21   =&gt; x = 12   12nswer : 12
<result>A</result>
A wheel that has 12 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: