The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is
A. commutative only
B. associative only
C. both commutative and associative
D. none of these
Answer:C
The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is
A. commutative only B. associative only C. both commutative and associative D. none of these