Even I know that's not how percentages work

I got this hairbrush.

If there's 45% less breakage and 55% less effort, you don't add them together to get 100%.

The total percentage of overall benefit can't be more than the highest individual benefit. And if any of the individual benefits is not 100, the overall benefit can't be 100.

So (assuming breakage and effort are the only factors that contribute to 'happy hair'), I think (and my maths could be wrong) they add up to 50% happier hair - the average of the two. Which is still a good percentage.

Percentages aside, I think it does a good job - definitely much less breakage. Effort - easier than dragging a comb through it, but have to go over it more times. Happier hair? I haven't asked it how it feels 😊

 

[Edit: after a lengthy discussion with my brother (we do talk about interesting things 😁) I have concluded that a) my percentage was too simplistic, but that was partly because b) the whole thing is like comparing apples and oranges and makes no sense whatsoever.]