[tex]1.Calculating\ volume \ of \ the\ swimming\ pool:\\\\
V=a*b*c\\
a=30 feet,\ b=20feet,\ c=5feet\\\\
V=30*20*5=
3000 feet^3\\\\
There\ are\ 7,5 \ gallons\ of\ water\ in\ 1 \ cubic\ feet\ so:\\\\ V*7,5 gallons=3000*7,5=22500 gallons\\\\
Answer:\ 22500\ gallons\ swimming\ pool\ can\ hold.[/tex]