The question requires us to add up the fractions to get our value of the total.
The steps to get that is stated below
[tex]\frac{2}{3}+\frac{3}{8}+\frac{2}{8}[/tex]To add up these fractions, we need to get the Lowest common Multiple to get a common denominator. I.e, a number that is the lowest number that 3 and 8 divide without remainder. This number is 3 x 8 = 24
[tex]\begin{gathered} \frac{2}{3}\text{ becomes }\frac{2\times8}{3\times8}=\frac{16}{24} \\ \frac{3}{8}\text{ becomes}\frac{3\times3}{3\times3}=\frac{9}{24} \\ \frac{2}{8}\text{ becomes}\frac{2\times3}{3\times3}=\frac{6}{24} \end{gathered}[/tex]Thus, we now have a common denominator for all the fractions and the numerators can now be added as:
[tex]\frac{2}{3}+\frac{3}{8}+\frac{2}{8}=\frac{16}{24}+\frac{9}{24}+\frac{6}{24}=\frac{16+9+6}{24}=\frac{31}{24}\text{ gallons}[/tex]In mixed fraction form, we have
[tex]1\frac{7}{24}\text{ gallons}[/tex]In decimal, we have 1.29 gallons