Score: the law of equal areas indicates that planets travel slower equal areas equal distances faster when they are closer to the sun, and equal areas faster equal distances slower when they are farther out from the sun.

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?