Wholesale Globes

How many globes can be painted?

A school supply company coats its cardboard globes with lacquer. Each globe has a circumference of 93 cm. One litre of laquer covers 12 m squared. How many globes can be painted with 1 L of lacquer? *Answer is 43 globes. Please show your work! Thank you!

Public Comments

1. Surface area of sphere = 4pi(r^2) Circumference of sphere = 2pi r 93cm = 2pi r Therefore r = 93 / 2pi Sub in to Surface area formula: SA = 4pi (93 / 2pi)^2 = 4pi (93^2 / 4(pi^2)) = 93^2 / pi = 2753 cm^2 12 m^2 = 120,000 cm^2 Therefore result = 120,000 cm^2 / 2753 cm^2 = 43.6 spheres for 1 L of lacquer. But we round down, so 43 globes.