How to solve pls once show steps... .. . . . . . . . . .

U(27) have 18 elements ={ 1,2,4,5,7,8,10,11,13,14,16,17,19,20,22,23,25,26} hence this group is isomorphic to Z(18) group Z(18) is cyclic group and it's divisors is 6 hence total n...