Express $0.7 \overline{39}$ in the form $\frac{P}{q} ;$ where $p$ and $q$ are integers and $q \neq 0$

Is $\sqrt{8+15}$ a rational number or an irrational number ?

State the number which is a whole number but not a natural number.

Simplify the following:

$\frac{\sqrt{24}}{8}+\frac{\sqrt{54}}{9}$

Classify the following numbers as rational or irrational with justification:

$(i)$ $-\sqrt{0.4}$

$(ii)$ $\frac{\sqrt{12}}{\sqrt{75}}$

Insert a rational number and an irrational number between the following:

$6.375289$ and $6.375738$