The volume of the cylinder is
![V=\pi\text{ }* r^2* h](https://img.qammunity.org/2023/formulas/mathematics/college/4yri3uk35jz1hr48mmuk2eksc395jfn3ah.png)
The diameter of the cylinder is 25 feet, then
The radius of it = 1/2 x diameter
![r=(1)/(2)*25=12.5ft](https://img.qammunity.org/2023/formulas/mathematics/college/mujr8y271q8761sxboxslsukme84zbmat9.png)
Since the height is 4.5 ft
Substitute them in the rule above
![\begin{gathered} V=3.14*(12.5)^2*4.5 \\ V=2207.8125ft^3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/c080fynrnqwvj1r453quzcq0qavywwdza9.png)
Now we will change the cubic feet to gallons
![\because1ft^3=7.48\text{ gallons}](https://img.qammunity.org/2023/formulas/mathematics/college/80f6pswq5s70hfwcs26bdgg81cf4egliq8.png)
Then multiply the volume by 7.48 to find the number of gallons
![7.48*2207.8125=16514.4375gallons](https://img.qammunity.org/2023/formulas/mathematics/college/8ph7xxy1o0vavod5y3rdild9ar14stz28c.png)
Now let us divide the number of gallons by 3000 to find how many gallons of liquid chlorin he needs to buy
![(16514.4375)/(3000)=5.5048125](https://img.qammunity.org/2023/formulas/mathematics/college/qskhp9ku0h33st1vsyym8o45ceuwwmvgv4.png)
Then he has to buy 6 full gallons