\begin{examplebox} \subsection{Worked Examples} \begin{multicols}{2} \begin{doublespace} \begin{minipage}{0.5\textwidth} \subsubsection*{Question 1} Write \(0 . \dot{2}\) as a fraction. \subsubsection*{Solution 1} Let \(\quad S=0 . \dot{2}\) So \(\quad S=0.2222 \ldots\) Then \(\quad 10 S=2.2222 \ldots \quad\) (Multiply by 10.) \(10 S=2+0.222 \ldots\) Therefore \(10 S=S+2\) Hence \(\quad 9 S=2\) So \(\quad S=\frac{2}{9}\) Thus \(\quad 0 . \dot{2}=\frac{2}{9}\) \end{minipage} \begin{minipage}{0.5\textwidth} \subsubsection*{Question 2} Write 0.12 as a fraction. \subsubsection*{Solution 2} Let \(\quad S=0.12\) So \(\quad S=0.12121212 \ldots\) Then \(\quad 100 S=12121212 \ldots\) Therefore \(100 S=12+S\) Hence \(\quad 99 S=12\) So \(\quad S=\frac{12}{99} = \frac{4}{33}\) Thus \(\quad 0 . \dot{1} \dot{2}=\frac{4}{33}\) \end{minipage} \end{doublespace} \end{multicols} \end{examplebox} \begin{exercisebox} \subsection{Exercises} \begin{questions}\begin{onehalfspacing} \Question[10] \begin{parts} \begin{multicols}{2} \part \(0 . \dot{5}=\frac{5}{9}\) \part \(0 . \dot{7}=\frac{7}{9}\) \part \(0 . \dot{9}=\frac{9}{9}=1\) \part \(0.1 \dot{4}=\frac{14}{99}\) \part \(0.2 \dot{3}=\frac{23}{99}\) \part \(0.6 \dot{2}=\frac{62}{99}\) \part \(0 . \dot{1} \dot{3}=\frac{13}{99}\) \part \(0 . \dot{0} 7=\frac{7}{90}\) \part \(0 . \dot{9} \dot{1}=\frac{91}{99}\) \part \(0 . \dot{2} 4 \dot{1}=\frac{239}{990}\) \end{multicols} \begin{multicols}{4} \part Which of these numbers are irrational? \begin{enumerate} \item[\CheckedBox] \(\sqrt{7}\) \item[\Square] \(\sqrt{25}\) \item[\Square] \(0 . \dot{6}\) \item[\CheckedBox] \(\frac{\pi}{3}\) \end{enumerate} \end{multicols} \end{parts} \end{onehalfspacing}\end{questions} \end{exercisebox}