A maths puzzle is boggling minds around the world, but can you solve it?

The test has been shared by thousands on Facebook after it was posted by the page Wikr.com.

To solve the problem, you simply have to work out the number to replace the question mark.

According to Wikr.com, only one in every 1,000 people can master it.

*(Read on to discover the answer.)*

While one plus four does indeed equal five, two plus five does not equal 12. So, what’s the catch?

The puzzle actually has a few possible solutions.

### Solution One:

1 + 4 = 5

Then on the next line, add the answer from the previous equation to 2 + 5. That gives you the answer of 12.

The rest of the list will go as follows:

12 + 3 + 6 = 21

21 + 8 + 11 = 40

### Solution Two:

1 + 4 = 5. You could also reach that answer by adding 1 to 4 multiplied by 1.

With the second line, it would be: 2 + (2 x 5) = 12

The rest of the list will go as follows:

3 + (3 x 6) = 21

8 + (8 x 11) = 96

So to solve the puzzle, you can either give the answer 40 or 96.

### Solution Three:

Solution three is a little more complex to explain. For you super mathematicians, the answer would be would be 201 using the following sequence:

5 = 5 using base 6

7 = 12 using base 5

9 = 21 using base 4

19 = 201 using base 3

If that sounds like gobbledygook, you’ll find an explainer of base conversions here.

Headache? Us too.

H/T: wikr.com