Question

To allow the pump of the fish tank to work properly and avoid water overflowing, the fish tank should be filled up to 7/8 of its capacity. Emily bought a 64-gallon fish tank and filled up the fish tank with 13 gallons of salt water. How much more water should she add?

Answer 1

The fish tank has a capacity of 64 gallons, and Emily has already filled 13 gallons of salt water. So, the amount of space left for water is:

64 - 13 = 51 gallons

To fill the fish tank to 7/8 of its capacity, Emily needs to add:

(7/8) x 64 = 56 gallons

Since she has already added 13 gallons of salt water, Emily needs to add:

56 - 13 = 43 gallons

Therefore, Emily needs to add 43 gallons of water to fill the fish tank to 7/8 of its capacity.