A cylindrical gasoline tank is 50 ft high and has diameter 70 ft. How many gallons of gasoline will the tank hold if there are 7.5 gallons in 1 ft3?

Let's start with what we know.

Height (h) = 50ft

Diameter (d) = 70ft

1ft³ = 7.5 gallons

To answer this, we first need to know the equation used to calculate the volume of a cylinder:

V = πr²h

Looking at that equation, you might notice it requires the radius (r) while we only have the diameter. Fortunately, the radius is simply one-half of the diameter so:

d/2 = r

70ft/2 = r

r = 35ft

Now that we know r, we can calculate the volume of the tank:

V = πr²h

V = π x (35) ² x (50)

V = π x 1225 x 50

V = π x 61250

V ≈ 192422.6 ft³ when you round to the nearest tenth

So now we know this tank's volume is 192,422.6ft³

Since 1ft³ = 7.5 gallons, we can multiply 7.5 by the volume to see how much gas it can hold.

7.5 x 192422.6 = 1,443,165 gallons of gasoline