The formula shows the brightness of the light of an object, which varies inversely as the square of the distance. L, measured in lumens, is the brightness of the light and d, measured in meters, is the distance from the object to the light source.

The brightness of an object was measured d meters away from a light source. The brightness of the same object was measured 1.5d meters from the light source. What is the ratio of brightness of the object when it is close to the light source to when it is farther away from the light source?

Transcribed Image Text:

P d² k = 7