Only those with eyes like a hawk will spot the hidden number in just 9 seconds

One of the best things about brainteasers is their variety, their colour, and the different forms they can come in.

There are three main types of brainteaser, observational brainteasers, mathematical brainteasers, and analytical brainteasers.

Mathematical brainteasers pose a maths question to the user who then has to solve that problem as quickly as possible. Analytical brainteasers often pose a written riddle or other form of tongue twister that needs to be unravelled.

Observational brainteasers such as the one above by Jagran Josh may seem simple at first but still require the user to think because they often task someone with finding an anomaly in an image.

In the graphic above, people are faced with what looks like a blank yellow page, but within this page is a number. The goal of this brainteaser is to work out what that number is.

Did you spot the number? No worries if not, it is outlined above. If you looked closely you would have spotted the number 725.

The key to this brainteaser is to focus on the image and look through the parts of the image trying to obscure the truth to see a faint outline of the number.

Brainteasers such as this one are great for stretching the mind and giving the brain some helpful exercise. They can be beneficial to the mind in the same way that running or cycling can help the muscles in the arms and legs.

Similarly to physical exercise, psychological exercise such as this one could help keep the brain healthy in the long term.

This doesn’t mean that brainteasers will stop someone from developing dementia or other neurological conditions, but they could help keep it sharper for slightly longer.

One thing that can contribute to improved neurological health is physical exercise. According to one study, as little as 4,000 steps a day could be enough to stave off Alzheimer’s disease.

Co-author of the study Dr David Merrill said: “We found that even moderate levels of physical activity, such as taking fewer than 4,000 steps a day, can have a positive effect on brain health. This is much less than the often-suggested 10,000 steps, making it a more achievable goal for many people."

Fellow co-author Dr Somayeh Meysami added: “Our research links regular physical activity to larger brain volumes, suggesting neuroprotective benefits. This large sample study furthers our understanding of lifestyle factors in brain health and dementia prevention.”