Explanation
(a). Completing the table as follows



\(\oplus\)
2
3
4


2
4
0
1


3
0
1
2


4
1
2
3







\(\otimes\)
2
3
4


2
4
1
3


3
1
4
2


4
3
2
1



(a) (ii) (a), they obtained the value of e as 1.
(a) (ii) (b), the value of n was 2.

(b), they couldn't answer this question correctly. If p = q, then:
(i) q \(\Rightarrow\) p, this is invalid
(ii) \(sin\) q \(\Rightarrow\) \(sin\) p, this is valid
(iii) \(sin\) p \(\Rightarrow\) \(sin\) q, this is invalid


