Arrange $\dfrac{5}{8}, -\dfrac{3}{16}, -\dfrac{1}{4} \text{ and } \dfrac{17}{32}$ in the descending order of their magnitudes.

Also, find the sum of the lowest and the largest of these rational numbers. Express the result obtained as a decimal fraction correct to two decimal places.

Without doing any actual division, find which of the following rational numbers have terminating decimal representation :

(i) $\dfrac{7}{16}$

(ii) $\dfrac{23}{125}$

(iii) $\dfrac{9}{14}$

(iv) $\dfrac{32}{45}$

(v) $\dfrac{43}{50}$

$\sqrt{8}(\sqrt{8} - 1)$ is always :

1. rational

2. irrational

3. whole number

4. natural number

For the given figure length of OA is :

1. $\sqrt{5}$

2. $\sqrt{3}$

3. $\sqrt{5} \text{ or } \sqrt{3}$

4. neither $\sqrt{5}$ nor $\sqrt{3}$