There are 6 balls in the urn. A blue ball was lowered into it. Then they pulled out 1 ball. Find the probability

There are 6 balls in the urn. A blue ball was lowered into it. Then they pulled out 1 ball. Find the probability that it will be blue if all the possibilities about the initial composition of the balls by color are equally probable.

After one blue ball was lowered into the urn to the already existing six, we got 7 balls. Of these, 1 is blue and 6 of a different color. The probability is found by dividing the lower number by the higher, so we divide the one (1) ball we pulled out by the seven (7) balls in the urn. That is, with an action of 1/7, the probability is one in seven.
Answer: 1/7 or one in seven.