Question
Linear Algebra Question on Groups
For a positive integer n, let U(n) = {rˉ ∈ ℤn ∶ gcd(r, n) = 1} be the group under multiplication modulo n. Then, which one of the following statements is TRUE ?
A
U(5) is isomorphic to U(8)
B
U(10) is isomorphic to U(12)
C
U(8) is isomorphic to U(10)
D
U(8) is isomorphic to U(12)
Answer
U(8) is isomorphic to U(12)
Explanation
Solution
The correct option is (D) : U(8) is isomorphic to U(12).