Question

A fish tank holds 35 {\rm gal} of water. Using the density of 1.0 {\rm g/mL} for water, determine the number of pounds of water in the fish tank

Answer 1

1 gallon of water weighs 8.34 pounds

Multiply that by 35 gallons.

You don't need the density; it is already assumed in the 8.34 lb/gallon figure.

Answer 2

292 lb