# 10 Photos That Definitively Prove Math Is Really Hard

Staff member

#### MarkFL

Staff member

My favorite is the quadratic equation...because that's the kind of typo I might make.

#### Farmtalk

##### Active member
Thanks for sharing! I like #2, but they are all funny!

##### Active member
#2 seems to be a case of sneaky advertising. It's 10 calories!!! ...per half the bottle, that is, per "8 fluid oz". I don't think the others have such a justification though. I guess the quadratic formula holds for quadratics of the form $ax^2 + b(x+1)=0$.

#### Klaas van Aarsen

##### MHB Seeker
Staff member
#2 seems to be a case of sneaky advertising. It's 10 calories!!! ...per half the bottle, that is, per "8 fluid oz".
Yeah. And doubling half the bottle gives us... erm... 20 fluid oz!

In other words, 8 fluid oz should be 8 calories.
But then, these are bold calories!!

#### Evgeny.Makarov

##### Well-known member
MHB Math Scholar
Regarding #1 (two \$1.69 burritos for \$4) and #6 (two \$2.97 bottles of body wash for \$6.97), I call it a violation of the triangle inequality: buying two things at once costs more than buying them in turn. This seems strange, but then the following joke come to mind. Two panhandlers sitting next to each other have notices in front of them. One says, "Please give to a Vietnam veteran", and the other one says, "Don't want to work". Everybody gives money to the first guy, and his mug is almost full, while the mug of the second guy is empty. One of the passers-by tells the second guy, "You've got to change your notice like the other one". He turns to his neighbor and says, "Listen to him! He is going to teach us commerce!" So, who am I to teach these stores commerce? Maybe they are enticing customers to buy two things by letting them think they are ripping the store off.

Several other pictures can be explained. Number 10 ("Was 8.00, now 7.50, save 1.00) is correct if you buy two things. Number 9 ("Was \$52.99, now \$47.99, you save \\$12") writes the saving in base 3. Number 5 ("We wanted to increase deliciousness by 200%") implies that originally a pack contained 2/3 of a bar. In fact, deliciousness is arguably a non-additive quantity like temperature: when you put two bars together, their temperature is not added.

Number 4 (drawn 11 nuggets instead of 10) is no different from any other fast-food advertisement where sandwiches look better and bigger than they do in reality. And concerning two cups with sauces, I want to tell Americans how lucky they are. In some other countries (even first-world ones), one has to buy sauces and dips separately. The worst case of this is a fast-food restaurant I knew where one had to buy Caesar salad sauce in addition to the salad itself. That place went out of business.