Random reposts - 3

I could not prevent myself from ranting about this.

The following thing has been floating around Facebook for a few days now.
1+4=5
2+5=12
3+6=21
5+8=???

Always it is accompanied by something like "I failed to solve this, so had to change profile pic".

NO.

I don't know what your answer is but very likely you did not fail. This is not a "properly" defined problem. In the very simplistic sense I could take the binary operator a + b to mean a*(b+1) and say the last thing is 45. The fact that 1+4=5 has nothing to do with that solution.
I could again say a+(a+3) actually means a^2+4a. That again is a perfectly valid solution. (In fact it gives the same value as before).

Now, the functions above are both quadratic terms. We can try cubic polynomials to define the problem. We can try any higher order polynomial that 

This is NOT some clever problem that tricks people. This is a very VERY poorly defined problem. That's it.

PS: I understand some of you just enjoy doing things like this in Facebook and enjoy changing their profile pictures to weird things and are happy to do weird trend-y stuff. I apologize if I seem like a killjoy. Just couldn't take so many people being in a "GOTCHA" mood over nothing.

PS: I had made this post in Facebook, where the context seemed clear to most people. However, probably adding a bit context here would be good. The actual text going around with the problem was "find the correct one". And the reply came as 1+4=5 is the only "correct" one according to regular arithmetic, the proper answer would be "1+4=5 is the correct one".
...
Stupid.
Yes.
I know.

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