Question 789388
The radius of the tank is 2.5, we assume that the radius is 2.5 meters
The surface area of a sphere is given by 4 * pi * r^2 so we calculate
4 * 22/7 * 2.5^2 = 78.53981633974483096157
now divide 78.53981633974483096157 by 12 = 6.54498469497873591346
this tells us we need at most 7 gallons