doubleKO said:

Here's one that's pretty easy without any maths. I certainly don't want to encourage any more of those type of "riddles".

A man was on his way home. He saw a masked man standing in his path holding something in his hand. He turned and ran back the way he came. What did the masked man have in his hand?

Most obvious answer is a gun...which means that's not it.

Man, some of these are really tricky or are very open. It could be a sign that says, "Hey Mister, you left your keys at the office and your wife's been wondering where you are for over an hour." I dunno.