Final answer:
The probability that a ball drawn is neither black nor white from a bag with 3 white, 4 red, and 5 black balls is 1/3.
Step-by-step explanation:
The question asks for the probability that a ball drawn is neither black nor white from a bag that contains 3 white, 4 red, and 5 black balls. To calculate this probability, we first determine the total number of balls, which is 3 + 4 + 5 = 12. Next, we identify that the only remaining color that is neither black nor white is red. There are 4 red balls in the bag. So the probability is determined by dividing the number of red balls by the total number of balls. Therefore, the probability is 4/12, which simplifies to 1/3.