Answer :
[tex]Volume \ of \ a \ Cuboid: \\ \\ V=9000 m^3 \\the \ length : \ l=20 \ m \\ the \ height: \ h=3 m \\ the \ width : \ w= ? \\ \\V= l\cdot w \cdot h \\ \\900 =20 \cdot w \cdot 3 \\ \\900=60w \ \ / :60\\ \\ w=15 \ m \\\\Answer : \ A \ swimming \ holds \ 15 \ meters\ the \ width .
[/tex]