"For any two real numbers x and y, x+y=y+x" is one of the condition in what binary operation?

"The product of any two real numbers is also a real number" is one of the condition in what binary operation?

"For any real numbers x, x+0=x." is one of the condition in what binary operation?

"For any three real numbers x, y, and z, x∙(y∙z)=(x∙y)∙z" is one of the condition in what binary operation?

A binary operation is said to be commutative if:a.a * b = 1 for all values of a and bb.a * b = a for all values of a and bc.a * b = b for all values of a and bd.a * b = b * a for all values of a and b

Let ‘&’ be a binary operation defined on the set N. Which of the following definitions is commutative but not associative?