Please help me. I can´t figure it out.

Answer:
[tex]\frac{1}{2}[/tex] glasses
Step-by-step explanation:
The ounce part does not matter because you are trying to figure out how many glasses of water she drinks in a hour.
[tex]\frac{2}{3}[/tex]g = [tex]\frac{4}{3}[/tex]h
divide by 4 to get the hour fraction easy to work with
[tex]\frac{1}{6}[/tex]g = [tex]\frac{1}{3}[/tex]h
times by three to get one hour
[tex]\frac{3}{6}[/tex]g = [tex]\frac{1}{1}[/tex]h
your answer is 0.5 glasses or [tex]\frac{1}{2}[/tex] glasses