Question

a septic tank has the shape shown to the right. how many gallons does it hold? (1 ft³ ≈ 7.48 gallons)
the tank holds □ gal (round to the nearest gallon as needed.)

Explanation:

Step1: Calculate the volume of the cylindrical - like part

The septic tank can be considered as a combination of a cylinder - like shape. The formula for the volume of a cylinder is $V=\pi r^{2}h$. The diameter $d = 2$ ft, so the radius $r=\frac{d}{2}=1$ ft and the length $h = 5$ ft. Then $V=\pi\times(1)^{2}\times5 = 5\pi$ $ft^{3}$.

Step2: Convert the volume from cubic - feet to gallons

We know that $1$ $ft^{3}\approx7.48$ gallons. So the volume in gallons $V_{g}=5\pi\times7.48$.
$V_{g}=5\times3.14\times7.48= 117.436\approx117$ gallons.

Answer:

117