a)
[tex]x=0.\overline{24}\\
100x=24.\overline{24}\\
100x-x=24.\overline{24}-0.\overline{24}\\
99x=24\\
x=\dfrac{24}{99}=\dfrac{8}{33}[/tex]
b)
[tex]x=0.2\overline{4}\\
10x=2.\overline{4}\\
100x=24.\overline{4}\\
100x-10x=24.\overline{4}-2.\overline{4}\\
90x=22\\
x=\dfrac{22}{90}=\dfrac{11}{45}[/tex]
c)
[tex]0.24=\dfrac{24}{100}=\dfrac{6}{25}[/tex]