Parking riddle has almost everyone stumped but answer is actually really easy

A crafty riddlehas left many scratching their heads, despite its simple solution.

Thisbrainteaser, which you can see below, requires a bit of patience and some clever thinking. Your task is to look at the numbers in the parking space and figure out what number is hidden under the blue car. According to Baba Mail, only five percent of people can solve this puzzle. If you're still puzzled, check out the answer below.

Here's a hint: if you can't figure it out at first, take your time and consider if there's another way to approach the problem. Are you looking at this riddle from the right perspective? In other news,only those with 'detective skills' can solve this.

READ MORE: Tricky A-level maths question stumps grown adults – so see if you can solve it

READ MORE: You might be working too hard if you can't find hidden key in less than 10 seconds

For those still baffled, the answer is 87. All you need to do is flip the picture upside down and everything becomes clear.

The numbers you can see: 16; 06; 68; 88 and 98 are in sequential order when viewed upside down. Brain teasers are a fantastic way to keep your mind active, but they can often be deceiving. Certain optical illusions can leave us feeling utterly perplexed.

The Dean McGee Eye Instituteexplained: "There are occasions when the brain is unsure of what it sees. Optical illusions occur when your eyes are presented with colours, lights, patterns, borders or areas of contrast that mislead the brain. It tries to piece together images using optical clues, learned assumptions and past visual experiences. In these cases, there is a difference between the reality of what you see and what your brain thinks you see. As a result, your brain makes a guess and is tricked into seeing something that does not exist, or it struggles to decide between alternating versions of an image."

READ MORE: Just 1% of people can find the elephant hidden in incredibly hard optical illusion

However, engaging in challenging puzzles, brainteasers and optical illusions could potentially enhance your cognitive function, productivity and memory.

Nicole M. Avena, PhD, assistant professor of neuroscience at the Mount Sinai School of Medicine in New York City and visiting professor of health psychology at Princeton University, stated: "While some studies show that brain training games are not effective, the recollection and work that the brain does during these games keeps your mind fresh and alert... Brain functions that you practise during these games-and the repetition of them-can help improve response time and sharpness."