Question 752644
surface area of a sphere is equal to 4 * pi * r^2


sphere A has a diameter that is 2 times the diameter of sphere B.


this means that sphere A has a radius that is 2 times the radius of sphere B.


if we let the radius of sphere B equal to x, then the radius of sphere A is equal to 2x.


the surface area of sphere A is equal to 4 * pi * (2x)^2 which is equal to 4 * pi * 4x^2 which is equal to 16 * pi * x^2


the surface area of sphere B is equal to 4 * pi * x^2 which is equal to 4 * pi * x^2.


the surface area of sphere A divided by the surface area of sphere B is equal to 16 * pi * x^2 / (4 * pi * x^2 which means that the surface area of sphere A is 4 times the surface area of sphere B.


if it took 9 gallons to cover sphere B, then it will take 36 gallons to cover sphere A.