$begingroup$ For (a), A straightforward way to take a look at is that you've minimized your chance Room to just the combinations which have no less than a single boy: $begingroup$ In stats and psychological investigation, what on earth is denoted by cash $N$ vs lowercase $n$? On the subject https://boyspggurgaonsector14.school.blog/2025/07/29/clean-and-secure-girls-pg-in-sector-14-gurgaon-book-via-osmstays/