The cylindrical bottle sells for $54.00, the conical bottle sells for $20.00 and the spherical bottle for $35. What is the best buy per cubic centimeter of perfume? Why?

1 answer

To determine the best buy per cubic centimeter of perfume, we must first calculate the volume of each bottle and then divide the cost by the volume.

The volume of a cylinder is given by the formula V = πr^2h, where r is the radius and h is the height. The cylindrical bottle has a height of 10 cm and a radius of 3 cm, so the volume is:

V_cylinder = π(3)^2(10) = 90π cm^3

The volume of a cone is given by the formula V = (1/3)πr^2h, where r is the radius and h is the height. The conical bottle has a height of 8 cm and a radius of 2 cm, so the volume is:

V_cone = (1/3)π(2)^2(8) = 16π cm^3

The volume of a sphere is given by the formula V = (4/3)πr^3, where r is the radius. The spherical bottle has a radius of 3 cm, so the volume is:

V_sphere = (4/3)π(3)^3 = 36π cm^3

Now, we can calculate the cost per cubic centimeter for each bottle:

Cost per cubic centimeter for the cylindrical bottle = $54.00/90π = $0.60/π ≈ $0.19
Cost per cubic centimeter for the conical bottle = $20.00/16π = $1.25/π ≈ $0.40
Cost per cubic centimeter for the spherical bottle = $35.00/36π ≈ $0.31

Therefore, the best buy per cubic centimeter of perfume is the cylindrical bottle at $0.19 per cubic centimeter. This is because the cylindrical bottle has the lowest cost per unit volume compared to the conical and spherical bottles.