You can
put this solution on YOUR website!First, find the volume of one cylindrical tank:

where: r = radius of the circular base and h = the height of the tank.
Radius = half the diameter.
r = D/2 = 6/2 = 3 ft.
h = 4 ft.
Use

as an approximation.
The volume of one tank is:

cu.ft. Multiply this by 7 to find the volume of 7 tanks.

cu.ft.
If 1 cu.ft = 7.5 gallons of liquid fertilizer, then:
791.28 cu.ft. = (7.5gal/cu.ft)(791.28cu.ft.) gallons.
This equals 5934.6 gallons.
So, the 7 tanks will hold 5934.6 gallons of liquid fertilizer.
You can
put this solution on YOUR website!V=B*H WHERE B= BASE AREA & H=HEIGHT
V=3.14*3^2*4
V=113.04 CUBIC FT. PER TANK.
7*113.04=791.28 TOTAL CUBIC FEET.
791.28*7.5=5,934.6 GALLONS OF FERTILIZER.