If i have a fish tank is 1/3 full of watet. If i add abither, 4 gallins of water it will be comoletely full. How many gallons would i need to make the tank 75% full

1/2 gallons

Step-by-step explanation:

since 1/3of the tank is already full and another 4 gallons fills it up

4 gallons = 2/3 of the tank or the tank is 6 gallons total

75% is equal to 3/4

6*3/4=4 1/2 gallons

since it is 1/3 or 4 gallons full

4 1/2 - 4 = 1/2