In an urn, there are several colored balls, with equal numbers of each color. We add 14 balls which are all of the same new color, that is different from those in the urn. It is calculated that the probability of drawing, without replacement, two balls of the same color is the same (when compared before and after the balls are added). How many balls are there in the urn initially?

Answer 1

Do check your previous post for answers before reposting!
See:
http://www.jiskha.com/display.cgi?id=1371911866