Show that $1.272727 \ldots=1 . \overline{27}$ . can be expressed in the form $\frac {p }{q }$, where $p$ and $q$ are integers and $q \ne 0$.
Let $x=1.272727 \ldots$ since two digits are repeating, we multiply $x$ by $100$ to get
$100 x=127.2727 \ldots$
So, $100 x=126+1.272727 \ldots=126+x$
Therefore, $100 x-x=126,$ i.e., $99 x=126$
i.e., $x=\frac{126}{99}=\frac{14}{11}$
You can check the reverse that $\frac{14}{11}=1 . \overline{27}$
Find an irrational number between $\frac {1}{7}$ and $\frac {2}{7}$
You know that $\frac{1}{7}=0 . \overline{142857}$. Can you predict what the decimal expansions of $\frac{2 }{7},\, \frac{3}{7}$, $\frac{4}{7},\, \frac{5}{7}, \,\frac{6}{7}$ are, without actually doing the long division ? If so, how ?
Visualize the representation of $5.3 \overline{7}$. on the number line upto $5$ decimal places, that is, up to $5.37777$.
Find five rational numbers between $1$ and $2$.
Rationalise the denominator of $\frac{1}{7+3 \sqrt{2}}$