The parts of the given question are solved below:

(a) We have,

,

We can observe that,

The numerator is a multiple of 3

And the denominator is a multiple of 5

Hence,

The next four rational numbers in this pattern are as follows:

… =

(i) Here, we have,

,

We can observe that,

The numerator is a multiple of 1

Denominator is a multiple of 4

Hence,

The next four rational numbers in this pattern are as follows:

, …

, …

(ii) Here, we have,

,

We can observe that,

The numerator is a multiple of 1

Denominator is a multiple of 6

Hence,

The next four rational numbers in this pattern are as follows:

, …

, …

(iii) Here, we have,

,

We can observe that,

The numerator is a multiple of 2

Denominator is a multiple of -3

Hence,

The next four rational numbers in this pattern are as follows:

, …

, …