I think I solved it, but I have the advantage of knowing when you graduated college and thus your approximate age.

Rebecca --- So what's your guess? I don't mind you outing our ages to the world and presumably anyone else will try to decipher the math before they scroll down.

37

Mark is 47 today right?

Mark's 47... You 37, (18 years = 71 and 61) 6 years ago, 41 and 31... Happy birthday...

You guys are math whizzes! I'm impressed!

yep I got 37 and 47.

I'm an artist and mostly allergic to math, but happy birthday Mark!

Hi All,

So much fun to read your column :).

Happy Birthday !!!!!!

John

It's close, but I don't think it's enough information without further knowledge. Here's what the data you supplied gives (using ipython because doing it by hand would be too tedious):

In [1]: import numpy as np

In [2]: primes = np.array([2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97])

In [3]: set(primes-6) & set(primes+6) & set(primes+18) & set(primes)
Out[3]: {23, 37, 47}

So the correct ages are in there.

If you were to add e.g. that there's 10 years between you, only one answer would remain;

In [4]: set(primes-6) & set(primes+6) & set(primes+18) & set(primes) & set(primes-10)
Out[4]: {37}

Deb -- Sorry to inflame your allergy!

Roland --- I love your mathematical analysis! Of course, the human reader would look at the header ("homesteading year 10") and realize that we can delete all numbers less than 28 assuming we began homesteading in adulthood. On the other hand, they might not be able to tell who is older --- me or Mark --- which would still leave two numbers in the possible solution set. So, you're right --- I need to add more data to my word problem next time around!

Happy Birthday! I, too, am allergic to Math. It gives me headaches. LOL