(i) \(\sqrt4 = 2 = \frac{2}{1}\)

\(\sqrt4\) can be written in the form of \(\frac{p}q\), so it is a rational number. Its decimal expansion is 2.0

(ii) \(3\sqrt{18}\) \(= 3\sqrt{{2 \times 3\times 3}}\)

\(=3 \times 3 \sqrt2\)

\(= 9\sqrt2\)

Since, the product of a rational and an irrational is an irrational number. 

Therefore,\(9\sqrt2\) is an irrational;

\(3\sqrt{18}\)  is an irrational number

(iii) We have,

\(\sqrt{1.44}\) \(= \frac{12}{10}\)

= 1.2

Every terminating decimal is a rational number, so 1.2 is a rational number. 

(iv) we have,

\(\sqrt\frac{9}{27}\) \(= \frac{3}{\sqrt{27}}\) \(\frac{3}{\sqrt{3\times 3\times 3}}\)

\(= \frac{1}{3}\)

Quotient of a rational and an irrational number is irrational number. Therefore, it is an irrational number.

(v) -\(\sqrt{64}\) \(= - \sqrt{8\times8}\)

= - 8 = -8/1

AS it can be expressed in the form of \(\frac{p}q,\) so it is a rational number

(vi) \(\sqrt{100}\) = 10 = \(\frac{10}{1}\)

Thus it can be expressed in the form of \(\frac{p}q,\) so it is a rational number.