3 / 4
Explanations:The given fractions are 6/12 , 9/18, 3/4, and 4/8
For 6/12
[tex]\begin{gathered} \text{Divide both the numerator and the denominator by 6} \\ \frac{6\div6}{12\div6}=\frac{1}{2} \end{gathered}[/tex]For 9/18
[tex]\begin{gathered} \text{Divide both the numerator and the denominator by 9} \\ \frac{9\div9}{18\div9}=\text{ }\frac{1}{2} \end{gathered}[/tex]For 3/4
3/4 is already the simplest term, It cannot be reduced further
For 4/8
[tex]\begin{gathered} \text{Divide both the numerator and the denominator by 4} \\ \frac{4\div4}{8\div4}=\text{ }\frac{1}{2} \end{gathered}[/tex]6/12, 9/18 and 4/8 reduced to 1/2 except 3/4
Therefore, 3/4 does not belong to the group
