Want to work your brain? **Try to take up this challenge**that has just resurfaced on social networks! This is a **mathematical problem **that seems rather simple, it is merely a short list of additions. However, when looking at the solutions to these problems you’ll grasp the complexity of the enigma.

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And indeed, since the problem has made its comeback on the web, it has once again triggered a lively debate among internet users.

**Here is the problem:**

1 + 4 = 5

2 + 5 = 12

3 + 6 = 21

8 + 11 = ?

The goal is obviously to find a solution to the last problem. Just by looking at the additions, one can guess that something is missing if you want to find the correct result and that the series actually follows a kind of pattern. Faced with this enigma, internet users have found two solutions using two different methods.

**Method number 1**

The first method is to **add the result of the previous operation** to the next. This is how it works:

1 + 4 = 5

5 + (2 + 5) = 12

12 + (3 + 6) = 21

With this method, we get the**answer****:** 21 + (8 + 11) = 40 then? = 40

**Method number 2**

The second method suggests that multiplication must be added to the process. More precisely, multiplying the second digit by the first as well as adding it is necessary. This is how it works:

1 + (4 x 1) = 5

2 + (5 x 2) = 12

3 + (6 x 3) = 21

With this method, **we get the answer:** 8 + (11 x 8) = 96 then? = 96

**The correct method?**

We could stop there and simply say that there are two ways to go about it. Except that according to the designers of the problem, there is only one. Which is the correct one? To answer this question, you must look at the series of operations a little closer.

We can easily see that the numbers follow a certain logic: 1 + 4 then 2 + 5 and 3 + 6. However, the 8 + 11 seems to break this logical sequence or at least, it seems to lack the steps of how to get there. Following this reasoning, normally one should have:

1 + 4 ; 2 + 5 ; 3 + 6then 4 + 7 ; 5 + 8 ; 6 + 9 ; 7 + 10and finally 8 + 11

Now let's apply the first method with the whole suite:

1 + 4 = 5

5 + (2 + 5) = 12

12 + (3 + 6) = 21

21 + (4 + 7) = 32

32 + (5 + 8) = 45

45 + (6 + 9) = 60

60 + (7 + 10) = 77

If we calculate the last operation, we get: 77 + (8 + 11) = 96 and not 40 like at the beginning

Now let's apply the second method:

1 + (4 x 1) = 5

2 + (5 x 2) = 12

3 + (6 x 3) = 21

4 + (7 x 4) = 32

5 + (8 x 5) = 45

6 + (9 x 6) = 60

7 + (10 x 7) = 77

With the last operation, we get: 8 + (11 x 8) = 96

Conclusion: although both methods can be considered to be correct, there is only one correct answer =>? = 96

**This maths problem** was posted on Facebook in April 2016 by Randall Jones, according to whom only one in 1,000 people can find the solution. \

How about you, were you able to figure it out?

**Check out the video above for more explanation!**