<PRE><B>Question 1120409</B>
I = k/D^2, where I is intensity and D is distance from source
:
Note k is the constant of proportionality
:
3 = k/5^2
:
k = 3 * 25 = 75
:
I = 75/15^2 = 75/225 = 1/3 foot_candle
:
answer is B.
:</PRE>