A puzzle for geniuses: find an unknown number as fast as you can

Puzzles are a great way to relieve stress, stimulate the brain, and improve cognitive skills and critical thinking. Experts say that daily training can reduce the risk of neurological diseases.

An interesting puzzle is gaining popularity online. You need to find the missing number in the shortest time possible.

Puzzles can help improve long-term and short-term memory, visual acuity, and attention to detail. As a nice bonus, such tasks distract you from everyday worries and promote a good mood.

Can you find the missing number in 7 seconds?

The correct answer

The unknown number can be calculated as follows:

4 + 8×2 = 20

9 + 3×2 = 15

Following the same pattern:

6 + 6×2 = 18

So, the missing number is 18.

By the way, MIT professor Shane Frederick has developed the shortest IQ test that will show you if you are smarter than 80% of people on Earth. You only need to answer three questions.

Earlier, OBOZREVATEL published a quick psychological test that will help determine whether you are a naive person.

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