turkey-yks 2010 Q8

turkey-yks · Other · lys1-math Groups Binary Operation Properties
Binary operations $*$, $\oplus$, $\odot$ defined on the set of rational numbers
I. $a * b = a - b$ II. $a \oplus b = a + b + ab$ III. $a \odot b = \frac{a+b}{5}$
are defined as follows. Accordingly, which of these operations satisfy the associative property?
A) Only I
B) Only II
C) Only III
D) I and II
E) II and III
Binary operations $*$, $\oplus$, $\odot$ defined on the set of rational numbers

I. $a * b = a - b$\\
II. $a \oplus b = a + b + ab$\\
III. $a \odot b = \frac{a+b}{5}$

are defined as follows. Accordingly, which of these operations satisfy the associative property?

A) Only I\\
B) Only II\\
C) Only III\\
D) I and II\\
E) II and III