Fig.15.21 shows the arrangement of wheels in a compound epicyclic gear train. The sun wheel S, is integral with the annular wheel 4,. The two arms are also integral with each other. Z == 24,z= 12=96. (a) If the shaft X rotates at 2000 rpm, find the speed of shaft Y, when A, is fixed. (b) At what speed does Y rotate when A rotates at 200 rpm, in the same direction as S,, which is rotating at 2000 rpm. 55 B B Fig.15.21 Compound epicyclic gear train