IN how mny ways can 18 white and 19 black balls be arranged in a row so that no two white balls may be together? It is given that balls ofteh same colour are identical.

In how many ways can 12 white and 8 black balls be arranged in a row if no two black balls are together?

In how many ways 4 different white balls and 6 different black balls be arranged in a row that no two white balls are together ?

In how many ways 4 different white balls and 6 different black balls be arranged in a row that no two white balls are together ?

In how many ways can 7 red and 6 black balls be arranged in a row, if no two black balls are together?

In how many ways can 21 identical white balls and 19 identical black balls be arranged in a row so that no 2 black balls are together?

Find the number of ways by which 4 green, 3 red and 2 white balls can be arranged in a row such that no two balls of the same colour are together. All balls of the same colour are identical.