Swiss photographer Tiziana Vergari took this photo of her children peering into some cleverly-arranged mirrors. How many children does she have? Well, that's the tricky part, isn't it?
Are you the Puzzlemaster? Let's see if you can figure it out.
If you're having trouble, don't worry. You may not be the Puzzlemaster, but you have that in common with the hundreds of people who have commented on the Instagram posts with their own guesses and theories as to how many children are in the picture.
For the record, Vergari commented on the post to say she only has two daughters(highlight for the answer). But don't let that bias your thinking! Quantum theory tells us that there technically could be an infinite number of Vergaris with an equally infinite number of daughters.
Imagine the possibilities.