Data with a smile - PG 6+ - episode 1

I stumbled across an interesting maths problem on Facebook, which is where I go when I take a break from trying to claim the 1 Million USD Millenium Prize by solving the Riemann Hypothesis during bio-breaks. ;-)

The problem was published on July 20th, 2021, under the intellectually arousing caption: "Solve if you are Genious", and was expressed in the following terms:

1 + 4 = 5

2 + 5 = 12

3 + 6 = 21

8 + 11 = ?

The problem was "liked" 1,5 million times and shared over 60 thousand times. Over 20 thousand mathematicians from all over the world gave it a shot and peer-reviewed each other's work, sometimes with scientific accuracy and sometimes with disparaging words and emoticons, thus proving that passionate mathematicians have feelings. It also made this conjecture a frontrunner candidate for the most studied maths problem of 2021.

The most common solutions were 8+11=40 and 8+11=91. Whilst a vigorous debate is still ongoing, both solutions were considered correct by over 5000 Facebook mathematicians, based on the following published workings:

Scrolling through the comments I found the answer of a dozen or so colleagues and friends (you know who you are) that fell evenly in both camps.

To try to put an end to the debate, I ran a Montecarlo Simulation, sampling all possible permutations of 8+11 and 11+8 over 10 thousand times. Surprisingly both the average and the mean outcome were 19!

I decided to go for a peer review of my results, with fellow mathematicians Emma (7 years old) and Paul (8 years old). For full disclosure, both are 1st-degree relationships of the author.

Both confirmed the validity of my observations and the scientific rigor of the method. So it seems like

8+11=19 QED

I hope this helps close the raging debate. In conclusion, 8+11=19, even if someone on the internet thinks that 2+5=12. And no, it's not an opinion... ;-D

The Data Guy