Clear your mind and focus on the task at hand, because this is much harder than it looks.
Brain teasers and puzzles are designed to test you. The answer is rarely obvious, and you need to really think outside the box. They can often be really tough, but in return, by doing them regularly, you can improve your brain's cognitive abilities.
Take the image below, for example. You'll see inside a school library, where children are going about their daily business. Some are reading books, others are walking, talking or sitting down.
But that's not all. There's loads going on in this image, and it's all there to distract you. You'll automatically see the clutter of books, backpacks, school supplies, posters and plants. But your mission is to find the hidden drinking straw.
According to puzzle creators Jagran Josh, you have "hawk-eye" vision if you can spot the hidden object within the 12 second timer. They explained: "This is a test of your sharp observation skills and quick thinking. Excelling in challenges like this is a hallmark of high IQ, superior cognitive abilities, and keen attention to detail."
You need "exceptional observational prowess", "sharp eyes" and "quick reflexes" to see it - especially as you'll be under time pressure. So set the timer and see how long it takes you to spot it.
Need a hint? Try looking in the top right-hand corner of the image. And we warn you, the answer isn't obvious. We told you that you need to think outside the box in order to find it. And if you give up, take a look below.
The answer is circled in the image above. You'll see that the window on the right looks different to the one on the left - as there's a drinking straw concealed within it. We told you it would be heard.
If you're feeling good, why not do another to prove yourself? Apparently only geniuses can work out what this next number is in this baffling maths sequence. And apparently most people can see two figures in this optical illusion, but only those with 20/20 vision can spot third.
And if you struggled with that one, how about a slightly easier challenge? You have 60 seconds to solve this nostalgic brain teaser, so the pressure won't be as high. But be warned, it's still not easy.
Did you manage to find the drinking straw? Let us know in the comment section below.