[tex]\frac{1}{8} \\ \\
\frac{3}{9}=\frac{3 \div 3}{9 \div 3}=\frac{1}{3} \\ \\
\frac{9}{18}=\frac{9 \div 9}{18 \div 9}=\frac{1}{2} \\ \\
\frac{6}{10}=\frac{6 \div 2}{10 \div 2}=\frac{3}{5}[/tex]
1/8 is the only fraction that can't be simplified, so Will should choose 1/8.
