Question

A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

Answer 1

You'd want an expression which relates to x, y and d.
The distance d is x times pi times 100. One divides back by pi and by y to get the # of revolutions (that 100 :)) ) and so one gets
`(100x)/(y)` as the number of revolutions.