I don't have to cheat to know the answer to this... though I'll agree that TOO MANY! is the best answer. :p

~*Aaryanna*~

@SomeGuy:

Tis sad, yes.

*slow nod*

*slapped*

@Kimmeh:

Poor mice . . . it's what sets them apart from the chimpanzees.

MICE CAN'T HAVE SEX WITH THEMSELVES...

=)

I think I got it right. XDD

I did the math for it, assuming that it was possible for mice to reproduce asexually, 'cause I'm a dork.

Month 01: 1
Month 02: 1
Month 03: (1) + 1·12 = 13
Month 04: (1) + 12 + 1·12 = 25
Month 05: (1) + 12 + 12 + 1·12 = 37
Month 06: (1 + 12) + 12 + 12 + 13·12 = 193
Month 07: (1 + 12 + 12) + 12 + 156 + 25·12 = 493
Month 08: (1 + 12 + 12 + 12) + 156 + 300 + 37·12 = 937
Month 09: (1 + 12 + 12 + 12 + 156) + 300 + 444 + 193·12 = 3,253
Month 10: (1 + 12 + 12 + 12 + 156 + 300) + 444 + 2,316 + 493·12 = 9,169

The numbers in parenthesis are the number of mice able to reproduce during that month. As you can see, the starter has to wait two months, then it gives birth to 12 more that get added for a total of 13. It will give birth twice more before those 12 are able to start reproducing two months later, at which point they get added to the parenthesis. Those, along with the starter, then produce 13·12=156 offspring, and from each month onwards after that one more group of offspring gets added to the pool able to reproduce.

Well since mice cannot reproduce asexually, unless you have one of each gender you'll still only have the original mouse after 10 months =P

And no, I didn't cheat ^^ This is just an easy question =P

Bah! I cheated... I like the Too Many! Answer the best. :p

-Sabrina

I cheated and looked at the spoiler stuff. Oh well... I wouldn't have gotten the right answer anyways. I like Someguy's answer the best.

Hahaha! I have only one short thing to say, though if you haven't answered the riddle yet, no cheating and looking under the spoiler tags! :p

You all are too smart for your own good!

I still like my Too Many! answer though. >_> Seriously, as if I'd ever go to a pet store and purchase a mouse. XP

I've seen this riddle before:

You have one since it's too young to be pregnant and you need a second one for it to get knocked up when it's two months old

I'm sure the other spoiler tagged answers are correct... *goes to look anyway*

I'll agree with the Too Many! Answer though... that's always correct when it comes to mice. >_>

~Crystia

Trick question! The answer is simple...

You have one since unless you had another one around to get the first one pregnant in two months when it was finally old enough to give birth, there's no way it would have had a litter on it's own.

*goes to look at what the others put*

-Darren

You have enough mice to warrant an infestation and to call the exterminator.

Let me say that you'll only have one mouse... it can't reproduce by itself, you know. Besides, there was no mention regarding any mice previously owned, so it is safe to assume that there are no other.

Well, how about that? Let me see what others have answered so far...

You'll have one mouse because a newborn can't have mated yet and you don't have any others for it to mate with later, and thus it has no way of reproducing.

I wanna say you'll have one mouse after ten months, because mice like other mammals are required to have sex in order to give birth to new mice; further, masturbation at present does not lead to pregnancy in mice or any other mammal just yet, so it seems fair to assume that the single mouse initially purchased will not be able to get itself knocked up without a second mouse around.

That feels like a good answer considering it's a riddle, so I'll go with that until someone comes up with a better answer.