## Deliver Us Not Into Bad Math

What better way to celebrate National Pizza Day than sharing this sign, which hangs in our local Pizza Hut:

Admittedly, I’ve never been very good with proportions, but even I know that

$\frac{3}{14} \ne \frac{5}{30}$.

Yet, that’s what’s implied by the statements for $3 and$5 in the sign. Further,

• For $1, you can feed 4 children for 1 day. That’s a daily rate of 25.0¢ per child. • For$3, you can feed 2 children for 7 days. That’s a daily rate of 21.4¢ per child.
• For $5, you can feed 1 child for 30 days. That’s a daily rate of 16.7¢ per child. Will the real price per child per day please stand up? And then I took a look at that last statement — that$10 can feed a classroom for a day — and it really blew my mind. Daily rates of 16.7 to 25.0¢ per child imply that classrooms have 40 to 60 students. I don’t know where these hungry students are, but maybe there should be a secondary campaign to reduce class size?

Though let’s be honest. What really seems to be needed here is an entirely new campaign:

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• 1. Joshua  |  March 2, 2015 at 3:36 am

Looks like unit pricing with a volume discount. However, I don’t know why that logic should apply to this type of donation.

• 2. James  |  March 2, 2015 at 9:27 am

There might be some kind of overhead and/or transaction fee(s) per child. This works out pretty close to the numbers on the sign if the fee were $0.40 per child per transaction, and each meal actually costs them$0.15. This would indicate a class size of around 13 kids.

• 3. venneblock  |  March 3, 2015 at 8:36 am

Good call, James. The three equations would be:
$4x + y = 1$
$14x + y = 3$
$30x + y = 5$
That gives the numbers you mentioned, though I think it’s a 40¢ fee per donation, not per child.

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