1/(2x2x2x2) for the odds of all roosters, 1/(2x2x2) for 3 roosters or hens, etc. It's been quite a while since I took a course that covered statistics/probability material, but I think it's right. 1/16 of a chance for all roosters or hens.
I’m going with this until mathman sees this! 🤣
1/2 x 1/2 x 1/2 x 1/2 for all four to be roosters.