Wendy's restaurant tweets simple algebra problem that erupts into debate | Hacker News Reader

Wendy's restaurant tweets simple algebra problem that erupts into debate

twitter.com

5 pointsVaslo4 comments

This is the same type of problem as the popular 2011 problem [1] of evaluating 48/2(9+3). The answer, really, is that it is ambiguous, so 8/2(2+2)/16 cannot be evaluated without further clarification or assumption. Any rule that anyone comes up with will not be widely accepted enough to be a convincing result.

The lesson is that you shouldn't write ambiguous expressions. 8/2(2+2)/16 is clearly worked out using the left-to-right rule, giving an answer of 1, while 8/(2(2+2))/16 gives 1/16.

[1] https://math.berkeley.edu/~gbergman/misc/numbers/ord_ops.htm...

I believe there is some precedent for interpreting implied multiplication as having a higher precedence than division [1]. The interesting thing, is that Wikipedia makes note of an Internet meme [2] based on this which uses the exact mathematical phrase `8/2(2+2)`. Based on this, I believe Wendys was very intentionally hoping to spark engagement based on a known controversial equation.

[1] https://en.wikipedia.org/wiki/Order_of_operations#Mixed_divi...

[2] https://knowyourmeme.com/memes/8222

Wendy's social media team are incredibly good at what they do, no doubt that it's intentional.

For equations, I kind of like:

                 . x      .   
           log  ( --- - sa )  
              e  ` m      '   
     y =  ────────────────────
                   2          
                  r

Reply on news.ycombinator.com