A circular rim 21 inches in diameter rotates the same number of inches per second as a circular rim 35 inches in diameter. If the smaller rim makes x revolutions per second, how many revolutions per minute does the larger rim makes in terms of x ?	Choose the correct choice from the following options
A) 48pi/x B) 75x C) 48x D) 45x E) x/75
Let's try the explanation. We have two wheels. One with 21pi and the other one with 35pi. They have the same speed. In the smaller wheel it's 21pi*x, which must be equal to the speed of the bigger one (35pi*a number of revolutions).They are asking that number of revolutions (but in minutes, which makes the question even harder).   Anyway, we have 21pi*x=35pi*a.   (21pi*x)/(35pi). As I said, that's in seconds. So, to convert it to minutes we multiply by 60 and we get the result, 45x.   Ans:45x
<result>D</result>
A circular rim 21 inches in diameter rotates the same number of inches per second as a circular rim 35 inches in diameter. If the smaller rim makes x revolutions per second, how many revolutions per minute does the larger rim makes in terms of x ?