There are variations on this maths meme, some have a cowboy theme, some have hamburgers, but the most recent has snowflakes on it. It doesn’t matter the solution is the same. Here’s the meme;
I saw this on Facebook and beneath it are thousands of comments with a range of answers, the six most common answers were; 15, 16, 17, 25, 60 and 70. Here’s the breakdown of the last 122 responses on the meme I saw.
The right answer is there, but it’s one of the lower scoring answers. So how are so many people getting it so wrong?
There are three errors people can make; two are observational, and one is to do with a convention in maths relating to the order of operations.
Here’s how to solve it.
Step 1 Snowflakes;
3 snowflakes = 30, so 1 snowflake = 10
Step 2 Candy Cane;
1 snowflake + 2 Candy Canes = 20, so 1 Candy Cane = 5
Step 3 Wine;
1 candy cane + four glasses of wine = 9, so one glass of wine = 1
I think this is the first place people make mistakes, they solve this equation as “wine= 2” which ruins their chances of solving step 4.
Step 4 Final Equation;
Candy cane = 5, 1 glass of wine = 1, snowflake 10, so the equation becomes;
5 + 1 x 10 = ?
Which looks really really easy, and if you put it into a calculator it gives you just one answer not 6, so what goes wrong?
Some people don’t notice that it’s a multiplication sign, and add it up to 16 – or 17 if they didn’t notice that it was just one glass of wine.
The next thing is that there is a maths convention around the order of operations that I learnt as “BODMAS”, which means that there is a correct order to do the addition and multiplication in. Multiplication comes first.
So the answer is 15. (Don’t believe me? Try putting it into a calculator.)
If you don’t use BODMAS, then you get 60 – or 70 if you didn’t notice the wine glass.
So that accounts for the correct answer and 4 of the most common incorrect answers. The least common incorrect answer is 25, which you get if you use the BODMAS convention but don’t realise there’s only one glass of wine.
Only 12% of my (not very random) sample got the right answer. The overwhelming majority 84% did not know/use the BODMAS convention, but presumably went to school at some point. Maths teachers the world over have been crying into their wine seeing the answers.
I’ve summarised the possible wrong answers into one handy image. Feel free to share.