Answer :
ANSWER
23/24 of the tank is filled with water
EXPLANATION
The tank can hold 800 gallons of water and you have 3/4 full:
[tex]800\times\frac{3}{4}=600[/tex]The tank has 600 gallons of water. Then you drain 100 gallons, so now you have 500 gallons of water in the tank.
Then, you add 1/3 of a tank. If one tank can hold 800 gallons, 1/3 of a tank is:
[tex]800\times\frac{1}{3}=266\frac{2}{3}[/tex]Therefore, you have 266 2/3 plus 500 gallons you had before:
[tex]500+266\frac{2}{3}=\frac{2300}{3}[/tex]To find what fraction of the tank that represents we have to divide it by 800:
[tex]\frac{2300}{3}\colon800=\frac{23}{24}[/tex]23/24 of the tank is filled with water.