First of all, the easy part- 5 gallons - [tex] \frac{3}{4} [/tex] is [tex]4 \frac{1}{2} [/tex]. An ounce is equal to 128 gallons, so we have to convert 6 x 8 ounces (48) to gallons. [tex] \frac{48}{128}= \frac{3}{8}[/tex] or 0.375 gallons. [tex]4 \frac{1}{2} [/tex] - [tex] \frac{3}{8}[/tex] =[tex]3 \frac{7}{8} [/tex] or 3.875 gallons left.