Ascientific theory a. describes what occurs every time in a given situation b. is not a validated bu experimentation c. can never be changed d. is an explanation for a set of events

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?