If you are in a public place, and overhear someone saying that they're looking for something but can't find it, is it rude or polite to tell them where it is?
Today I was in the grocery store, and an older gentleman was commenting to his son that he wanted to get some sauerkraut. He started looking for it, but was looking in the wrong places. I could tell, because I happened to be standing in front of the sauerkraut, which was on the lowest shelf, and not too easy to see. I know that it is normally polite to pretend as if you cannot hear the conversations of others in the aisle...but what about a situation like that, or one in which a person is looking at a map but saying they can't find a particular location? Is it impolite to offer the information they need?