Math Experts Split the Check

Engineer: Remember to tip 18%, everybody.

Mathematician: Is that 18% of the pre-tax total, or of the total with tax?

Physicist: You know, it’s simpler if we assume the system doesn’t have tax.

Computer Scientist: But it does have tax.

Physicist: Sure, but the numbers work out more cleanly if we don’t pay tax and tip. It’s a pretty small error term. Let’s not complicate things unnecessarily.

Engineer: What you call a “small error,” I call a “collapsed bridge.”

Economist: Forget it. Taxes are inefficient, anyway. They create deadweight loss.

Mathematician: There you go again…

Economist: I mean it! If there were no taxes, I would have ordered a second soda. But instead, the government intervened, and by increasing transaction costs, prevented an exchange that would have benefited both me and the restaurant.

Engineer: You did order a second soda.

Economist: In practice, yes. But my argument still holds in theory.

The computer scientist lays a smart phone on the table.

Computer Scientist: Okay, I’ve coded a program to help us compute the check.

Mathematician: Hmmph. Any idiot could do that. It’s a trivial problem.

Computer Scientist: Do you even know how to code?

Mathematician: Why bother? Learning to code is also a trivial problem.

Engineer: Uh… your program says we each owe \$8400.

Computer Scientist: Well, I haven’t de-bugged it yet, if that’s what you’re getting at.

Physicist: This is a waste of time. Let’s just split it evenly.

Economist: No! That’s so inefficient. Let’s each write down the amount we’re willing to put in, then auction off the remainder at some point on the contract curve.

Physicist: Huh?

Mathematician: Like most economics, that’s just gibberish with the word “auction” in it.

Engineer: Look, it’s simple. Total your items, add 8% tax, and 18% tip.

Mathematician: Sure. Does anybody know 12 plus 7?

Computer Scientist: You don’t?

Mathematician: What do I look like, a human calculator? Numbers are for children, half-wits, and bored cats.

The engineer looks at the cash they’ve gathered.

Engineer: Is everyone’s money in? It seems we’re a little short…

Physicist: How short?

Engineer: Well, the total was \$104, not including tip… and so far we’ve got \$31.07 and an old lottery ticket.

Physicist: Close enough, right? It’s a small error term.

Mathematician: Which of you idiots wasted your money on a lottery ticket?

Economist: I should mention that I’m not planning to eat here again. Are any of you?

Computer Scientist: What does that matter?

Economist: Well, in a non-iterated prisoner’s dilemma, the dominant strategy is to defect.

Engineer: Meaning?

Economist: We should be tipping 0%, since we’ll never see that waiter again.

Computer Scientist: That’s awful.

Physicist: Will the waiter really care – 0%, 20%? Let’s not split hairs. It’s a small error term.

The engineer looks up from a graphing calculator.

Engineer: All right. I’ve computed the precise amount each of us should pay, using double integrals and partial derivatives. I triple-checked my work.

Mathematician: Didn’t we all order the same thing? You could have just divided the total by five.

Engineer: I could? I mean… of course I could! Shut up! You think you’re so clever!

Economist: So, we’re all agreed on a 0% tip?

Computer Scientist: Well… the waiter did only bring two orders of fries for the table.

Physicist: We only ordered two.

Computer Scientist: Exactly. We got the 1st order, and the 2nd, but never the 0th.

Economist: I’ll be frank. At this point, my self-interest lies in not paying. And the economy prospers when we each pursue our individual self-interest. See you later!

The economist dashes off. The engineer and computer scientist glance at one another, then follow.

Mathematician: Looks like it’s just me and you, now.

Physicist: Good. The two-body problem will be easier to solve.

Mathematician: How?

Physicist: By reducing it to a one-body problem.

The physicist scampers away.

Mathematician: Wait! Come back here!

Waiter: I notice your friends have gone. Are you done with paying the check?

Mathematician: Well, I’ve got a proof that we can pay. But I warn you: it’s not constructive.

Thanks for reading! (And for your benign tolerance of my whiteboard doodles.) You might also enjoy “A Math Professor Consults on a Hollywood Movie.”

148 thoughts on “Math Experts Split the Check”

1. Reminds me of a RL scenario I was in. Here it is in simple terms:

Myself and 8 friends went out to another, recently deceased friend’s favirote resturant. I was feeling ill, and ordered only a single drink (for £1) and a single small portion dish (for £4, totalling £5).

Bill came round, I was last to pay, and ended up having to pay £30… Total for all 9 of us was £120.

Anyone want to work that one out for me..?

2. Thanks for a marvelous posting! I genuinely enjoyed reading it, you’re a great author.
I will remember to bookmark your blog and definitely will
come back in the future. I want to encourage you to continue your great job, have a nice afternoon!

3. The only thing i understand, that there will be chaos and confusion if various experts and specialists joins together and start giving their ideas. The best way should be the experts should be merely a listener and should keep their ideas within!!!!!!

• I didn’t think about that, but maybe this is the lesson…

4. Well you’re obviously a Computer Scientist. The comics recursively point to each other! How are you going to insert the next comic? A doubly-linked list would be much better. (Very funny, BTW.)

5. Why did it take twenty years of my life to find this post? So creative and awesome! I recently switched from a physics major to a mathematics major with a minor in management science. This is exactly what I needed to see!

6. Why were there only two orders of fries for five people if they all ordered the same thing?

• Good point. I’m wondering now, myself. :)

• “For the table” probably means it was ordered collectively, not by individuals (and therefore split evenly). Also, since they’re complaining, it’s possible the fries were complementary.

7. In Australia, tipping is not customary, and all quoted prices are inclusive of tax. So it’s easy to divide the bill.

When I was in California, I tipped the ‘typical’ 15% based on the after tax amount on the bill. Being Australian, I always consider the after tax amount by default. Being Chinese (by birth), I now wonder if I could have gotten away with tipping the 15% on the pretax amount. Lol.

• Since tipping is optional, you could have gotten away with 0% of either amount.

8. It weighed close to nothing, nevertheless the aunt finished up paying nearly \$150 in postage.

9. Very interesting, I was never good at math period!

10. i love math i learn how to solve a problem

11. you guys are unbelieveable. me, being an engineer was luaghing out loud.

Great one!

12. I would’ve stormed out of the restaurant on the basis they didn’t get the 0th order of fries

13. Haha brilliant! Being an engineer turned finance guy, I understood every aspect of this joke and it is hilarious. I was expecting the physicist to pull out something from quantam mechanics and start suggesting the infinite realities, in which no one has to pay. Anyway, great one.

14. The restaurant comment card picture made my day. I always forget to comment on my code too.
Even without that, this whole blog post is absolutely hilarious.

15. That group needs to sit down for another meal, and this time include a philosopher – so that he can include his logic – and a musician who can use his mathematical knowledge of notes and chords. Throw in an astronomer and it will make for even livelier discussion when the bill arrives.

16. OMG. This is so funny. Thank you! You are great in a very underdeveloped area ripe for humour!

17. Computer Scientist: But it does have tax.I would argue that it is generally more legitimate to break the law or to otherwise undertake direct non violent political action in order to challenge entrenched power than in order to reinforce it. best joint supplement