Facebook – Do Followers Get Notified When Liking a Post Comment as a Page?

same thing happened to me. this helps though:

http://www.readactor.com/articles/how-to-hide-all-friending-activity-on-facebook/

On the Facebook wall,on the right hand of your recent activity you’ll find a button from where you get two options, to remove the post (nothing new) and “hide all friending activity” A popup window needs your confirmation. Also there you have a link to your profile story settings manager. You can access at any time this settings.

Same thing and with the “like” notifier. You can now hide all “like” activity. Actually, you have now a more flexibility in set the privacy options for almost all things what are posted on your Facebook wall. Test this settings yourself!

The profile story settings manager unfortunately is not easy to be find. You can spend time to take a look in any profile or account setting but you never find it. The link for this settings is placed at very bottom of your Facebook wall. Scroll down your wall, wait to load stories, scroll again and there you will find the link pointed in the previous screenshot.

1. Friends of A may see A's activity in their news feeds in case 1.
2. Subscribers of B who also posted on A's post on B's wall may also see B's activity in their news feeds in case 2.
3. Subscribers of B may see B's activity in their news feeds in case 3.

Note that I use the word "may" because Facebook chooses what is relevant to show in News Feeds per user, based on each user's number of friends/subscriptions/specialize lists, the popularity of the post, etc. In any case, everything you can see should always show up in the news ticker, which takes more of a "fire hose" approach to showing updates, whereas the news feed attempts to show you only the most relevant news.

You can also read my earlier answers on visibility here and here.