In the urn there are 12 balls, 3 white and 7 black, the rest are red, find the probability that, at random

In the urn there are 12 balls, 3 white and 7 black, the rest are red, find the probability that, at random, the chosen ball is not white.

First, we find the probability that a white ball is removed from the urn:
P = 3/12 = 1/4.
Probability of the opposite event such that the removed ball is not white:
P` = 1 – P = 1 – 1/4 = 3/4 = 0.75.
Answer: The probability that the randomly chosen ball is not white is 0.75.