30,a) A = { 15,17,19,21,23}
B = { 17,15,21,19,23}
C = { 23.21.19.17.15}
b) A = {3,6,9,12,15,18,21,24,27,30}
B = { 9,6,3,12,15,18,21,24,27,30]
C = { 30,27,24,21,18,15,12,9,6,3}
c) A = [64,81,100,121,144,169,196]
B = { 8²,9²,10²,11²,12²,13²,14²}
C = { 196,169,144,121,100,81,64}