We have the following:
First we must seek equality between ounces and cups
1 cup = 8 oz
therefore
[tex]\begin{gathered} 3\cdot8+6=24+6=30 \\ 2\cdot8+9=25 \\ 30+25=55 \end{gathered}[/tex]Which means that in total there are 55 ounces
now we look for the equivalence of 55 ounces in cups and ounces
[tex]\begin{gathered} 5\cdot8+7=40+7=47 \\ 6\cdot8+7=48+7=55 \end{gathered}[/tex]The answer so is 6 cups and 7 oz
