Brain teasers and other mind boggling puzzles are an effective way of stretching the mind and pushing one of the body's most important muscles to its limit.
Such brain twisters can come in various forms whether it be analytical, mathematical or observational, the Express reports.However, this latest brain teaser from Freshers Live is an example of an observational riddle and if you can spot the odd one out in under 19 seconds, you're a true genius.
The above brain teaser shows a grid full of 899s but there is one different number hiding inside the box with brainteaser lovers being challenged to find it in just a third of a minute.
Did you manage to find the 869 in the rectangle? If not, the answer is below.How did you do? Let us know in the comments.If you're a fan of a good puzzle why not try out these other ones such as finding the hidden pumpkins in this autumnal setting or this tricky challenge of spotting the wolf in a pack of sheep, which requires '20/20 vision'.
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