Hey there!
0.75 gallons can be so many things.
You could multiply 0.75 gallons by 128 oz to get 96 oz.
You could multiply 0.75 gallons by 4 qt to get 3 qt.
You could multiply 0.75 gallons by 8 pt to get 6 pt.
You could multiply 0.75 gallons by 256 tbsp to get 192 tbsp.
Whatever you're looking for, just look up the conversion rate and multiply or divide your given amount of gallons accordingly. Next time you ask a question, you might want to specify what exactly you're looking for so that we can help you out even more.
Regardless, hope this helped you out! :-)
