I am new to the permutations. I have a problem with me for which I am not able to use proper formula -
Problem: There are X boxes in which balls need to be placed. The balls are of two colors - BLUE RED. We have unlimited balls of both colors. We need to find the number of permutations / ways in which the balls will be placed in the boxes in such a way that BLUE balls never come together.
Solution So far I have reached to the below formula- = (Total number of arrangements - Arrangements of BLUE balls sitting together) = (2^X - Arrangements of BLUE balls sitting together)
I am stuck for Arrangements of BLUE balls sitting together
What should be the right formula for this ?