1 + 4 = 5

2 + 5 = 12

3 + 6 = 21

8 + 11 = ?

19. Otherwise it's a logic problem.

But yes, it's 96. The formula is a + a × b.

And don't get me started on those fucking bodmas problems that litter my LinkedIn feed.

Whatever answer you want it to reach, it isn't reached through the standard rules of arithmetic and therefore the use of standard notation is not only misleading, but wrong.

That's why it's a load of shite

My answer is that they are not using base 10 and 8 + 11 has the quirk of adding up to 19 for bases, 10.11, 12, 20.. even 32.

Answer is 19.

If you rewrite it as a string of numbers then the first number after each "=" is the sum of the numbers between the previous ones; answer becomes 40.

1 + 4 = 5 2 + 5 = 12 3 + 6 = 21 8 + 11 = ?

They could be converting the base 10 answer into a series of reducing bases. The first answer is base 6, the second base 5, the third base 4 and the 8+11+19 becomes 201 in base 3.

Good spot, Gotout.

Can't be base 3. 8 and 9 don't exist in 3. It is any base 10 and above.

Even base 999

8 + 11 (1000) = 19 (1008)

Gotout's observation was that the sum itself is in dec, Fezzi, it's just the answers that are in other (declining) bases.

19 can't exist in base 3.

Certainly to do with bases other than 10.

Where does the question come from? Because Toastie's answer of 40 is what I had, based on it being the least unnecessarily complicated one.

Facebook group but I have seen similar before. It says it in the question only 1 in a 1000 people get it. Loads get 96 and and 40 so they can't be right. Those answers will only work with additional mathematical operators. They are not there.

Tommy's right. The notation is simply wrong. you can't just make + and = mean what you choose it to mean. If it was

1 4 5

2 5 12

3 6 21

8 11 ?

That would be one thing. But then you would notice that there's no logic to the 1, 2, 3, 8 unless they are in some way related. So I'd go with the 40, rather than the 96. The 96 doesn't explain why 1, 2, 3, 8.