(i) \(\sqrt{11}\) is an irrational number. (11 is not a perfect square number)
(ii) \(\sqrt{81}\) = 9 a rational number.
(iii) 0.0625 is a terminating decimal
∴ 0. 0625 is a rational number.
(iv) \(0.8 \bar3\) = 0.8333
The decimal expansion is non-terminating and recurring.
∴ \(0.8 \bar3\) is a rational number.