BosGuy brain teaser

Each Friday morning I post a riddle to get you to think outside the box and exercise your brain. If you are stumped, share it with a friend or colleague and see if you can figure out the answer together. Leave your answer in the comment section.

This week’s riddle: What has no weight, is visible to the naked eye, and when put inside a barrel, makes it lighter?

I’ll approve responses later in the day to give people a chance to respond without seeing any spoilers.

Like riddles? Check out past week’s brain teasers.