SOLUTION: The intensity I of light varies inversely as the square of the distance D from the source. If the intensity of illumination on a screen 5 ft from a light is 3 foot-candles, find th

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Question 113267: The intensity I of light varies inversely as the square of the distance D from the source. If the intensity of illumination on a screen 5 ft from a light is 3 foot-candles, find the intensity on a screen 15 ft from the light.
This is what I did...
y=k/x^2
3=k/5^2
3=k/25
k=75

y=75/x^2
y= 75/15^2
=75/225
=.333 footcandles

Is this correct?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Your answer is absolutely correct!
But I am puzzled as to why you did not use the same letters for the unknowns as given in the problem?
I+=+k%2FD%5E2