That depends on the type material you are referring to. Also, these are two different types of measurements. Gallons is a measure of volume but the other is weight or mass. Please edit your question to include more context or details.
92 gallons
It equals 3 gallons
A gallon is a unit of capacity. A pound is a unit of mass. The two units are therefore incompatible.
20 quarts equals 5 gallons
350 cups equals: 21.88 US gallons OR 18.23 UK gallons
61 gallons
4 gallons
5.943871 gallons
15 gallons
12 gallons
16 gallons
3 gallons