Light Intensity Homework: Solve for Unknown Intensity

[J89]

Homework Statement

A 60-cd lamp and a lamp of unknown intensity are placed 3m apart. A light meter is moved between the two lamps until it reads the same illuminance from both lamps. The light meter is then 1.5 m away from the 60-cd lamp. What is the intensity of the other lamp?

Homework Equations

E=P/d^2

The Attempt at a Solution

No clue

 

[rl.bhat]

Homework Statement

A 60-cd lamp and a lamp of unknown intensity are placed 3m apart. A light meter is moved between the two lamps until it reads the same illuminance from both lamps. The light meter is then 1.5 m away from the 60-cd lamp. What is the intensity of the other lamp?

Homework Equations

E=P/d^2

Use E = P₁/d₁^2 = P₂/d₂^2.
The point is whether the light meter is between the two lamps or outside the two lamps?