The question is asking for 2/3 times 3/4, or the 2/3 that they ate, out of the 3/4 total. This as an equation is
[tex]\frac{2}{3}*\frac{3}{4}[/tex]
You may notice the 3 on the top and on the bottom. Those will cancel out, leaving you with [tex]\frac{2}{4}[/tex], or [tex]\frac{1}{2}[/tex]
[tex]\frac{1}{2}[/tex]
