We have
1/2 liter apple juice ---- 1/3 of her glass
1-liter apple juice --- x
x is the number of glass filled with 1 liter
[tex]x=\frac{\frac{1}{3}}{\frac{1}{2}}=\frac{2}{3}[/tex]we can obtain equivalent fractions like
[tex]\frac{2}{3}=\frac{4}{6}[/tex]the answers are 2/3 and 4/6
