Final answer:
The probability that Julie will wear brown slacks and a white shirt is 1/4.
Step-by-step explanation:
To find the probability that Julie will wear brown slacks and a white shirt, we need to find the number of favorable outcomes and the total number of possible outcomes. Since Julie has two pairs of slacks (brown and black) and two shirts (white and gray), there are a total of 2*2=4 possible outfits she can wear. Out of these 4 outfits, there is only 1 outfit where she wears brown slacks and a white shirt. Therefore, the probability is 1/4, which is option c).