A number sequence has gone viral on the internet this week, reading: 2, 6, 12, 20, 30, ?. At first glance, it looks easy, but once people start solving it, they realize spotting the pattern is not so straightforward. The sequence looks familiar. Your brain immediately tries to apply simple arithmetic or geometric rules, and that is where it tricks you. The key here is to remain focused and keep trying out until you get the correct answer.
Also read: Optical Illusions: Understand how they fool your brain with these 5 examples
Maths Puzzle: Hint
Start by checking the differences between consecutive numbers. Look at each pair. Ask yourself: how does one number lead to the next? At first, you might think “add a constant.” But here, the differences themselves grow steadily. Slowing down and working step-by-step is the only way to crack it.
These number puzzles are not just fun, but they push your working memory, pattern recognition, and analytical thinking. That mix of expectation and surprise makes these puzzles addictive, the kind people can’t stop sharing.
Also read: Optical illusion: You have eagle eyes if you spot the odd word in 10 seconds
Maths Puzzle: Answer
Check the differences:
{{/usCountry}}Check the differences:
{{/usCountry}}6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10
Notice the differences go up by 2 each time. A tiny detail, but enough to fool anyone scanning too quickly.
Following the pattern, the next difference should be 12. Add that to the last number: 30 + 12 = 42. That moment when you finally solve it gives a sense of achievement; this is exactly what makes this puzzle so satisfying.
Why does it keep us hooked?
The puzzle works because it tricks our minds. It looks simple, but there is a subtle complexity hiding in plain sight. Our brain expects repetition. When it is forced to analyze carefully, the reward for solving it is immediate. That tension between ease and challenge is why it spreads so fast online.