I came up with an awesome math/logic problem stoned.

I came up with an amazing and really interesting (in my opinion) math/logic problem tonight while smoking a bowl and buzzing on a 30mg extended release adderall. Here it is, try and figure it out and if no one can after awhile I'll post the solution.

Suppose for some reason that the entire population of humans is nearing extinction. There are 4 humans left alive, all unrelated to each other. 2 males, and 2 females, all 18 years old. They are told to repopulate the planet without any inbreeding. For the sake of morality, step family (step siblings, parents, grandparents, great grandparents, children, grandchildren, great grandchildren, cousins, nephews, nieces, etc.) cannot breed together.

-Each male and female will be fertile until they are 37.
-A man can only have children with each woman two seperate times (So, a man and a woman will have a maximum of 4 children with each other).
-Whenever a woman gets pregnant and has children, it will always be twins and they will be a boy and a girl.
-When a child reaches 18 years of age, they will have their first children. They will have their second children when they reach 36 years of age.
-People die at the age of 73.

Using this information, answer the following:

[1] How many generations can these 2 families live for until there are no more possible unrelated combinations of males and females able to produce?

[2] How many people will have been alive after everyone dies out?

[3] What will have been the most people alive at one time?

[4] How many years will these people survive for?

It really isn't that easy, I was so focused on figuring this out though because of this Adderall that I sat down for at least an hour or more and wrote and drew out 2 family trees. I'll explain later how I came up with this problem. Bonus points if you can come up with hypothetical family trees. I'll translate mine to the computer and post it later.

whoa man thats crazy, i probably could figure it out but i am way too lazy :D and i cbf but meh, its still cool :)

alright i tryed to figure it out lol it gave me a head ache....i give up :( stupid maths

man what the fuck kind of weed were you smokin when you came up with that ?

Holy shit.

....Somebody is probably figuring it out as we speak.

That's some college grade shit right thurr!

i dont know if ive done it right but
1) can the grandchildren (2nd generation of children) have children with the original parents?

2)I dont think they would die out....because they would be creating new families....or somthing?? lol

3)36

4)72

5) i suck at math....but thanks for getting my brain a little active :)

Haha, ok. There is a numerical answer for every question. They will not continue to produce forever, eventually there will be a point where there are no more possible male/female combinations unless they breed with a relative. And the 3rd generation (first generation of grandchildren) cannot breed with the other family's original female (the one that would be the equivalent of their grandmother except in the other family) because the female would be 54 years old and infertile by the time the grandchildren reach 18, the age of maturity.

Hint: The fact that females can only have 4 children per male has a lot to do with it.

Oh and both your answers are wrong Az, but good try. ;)

Thanks LittLeWinG, and it's not too hard, just takes some time.

highjinx, I like to call it philosophical weed, or the thinking man's herb. :D

STDz, I'm a second year college student so that might explain why. :P

If a few more people respond and can't figure it out I'll post the solution. To be completely honest I'm insanely proud of coming up with this. I also came up with an experiment I'm going to write up (that's where this problem came from) and if I could ever get enough research grants and a few willing volunteers I would love to try it and write a book on it. This problem is fucking proof why pot should be legalized. I would've never thought of something this complex and thought out if I did not smoke.

cool i want to hear what your experiment is.....i love experiments....LOL>....

Here's a mind tickler-

1st-purchase large feather
2nd-insert into ear
3rd-poop

Sleep is for the weak.

How can it be that they can only have kids at ages 18-37?
That means they can only have kids twice in their lives...
By your own rules every COUPLE is sposed to have kids TOGETHER twice in their life...
Does that mean that every individual can have kids only with 2 others?

I may have confused myself there...all the above disregarding the rule of no interbreeding...We're taking that for granted...I'd really like to try and figure this out if you could gimme some info!!! :)

Dun take me wrong...all the above is subject to mistake...I'm no mathematician..