[SOLVED] STATS question help please

Hey, I just got this homework question on my first day at class and I don't have the text book yet so I was hoping someone on here could help me solve it. There's got to be some sort of formula.

Suppose a newly-born pair of rabbits, one male, one female, are put in a field. Rabbits are able to mate at the age of one month so that at the end of its second month a female can produce another pair of rabbits. Suppose that our rabbits never die and that the female always produces one new pair (one male, one female) every month from the second month on.

How many pairs will there be in one year?

Any help would be appreciated! Thanks