1980 AHSME Problem 10

The number of teeth in three meshed gears A, B, and C are x, y, and z, respectively. (The teeth on all gears are the same size and regularly spaced.) The angular speeds, in revolutions per minutes of A, B, and C are in the proportion

\text{(A)} \ x: y: z ~~\text{(B)} \ z: y: x ~~ \text{(C)} \ y: z: x~~ \text{(D)} \ yz: xz: xy ~~ \text{(E)} \ xz: yx: zy

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.