Hello forum :]

I am in need of some help on this probability problem.

The probability of being born on a Friday the 13th is 1/214. Assume the days of people's birth are independent of each other.

(a) You meet two new friends; what is the probability that both new friends were born on a Friday the 13th?

I got this one, just use the multiplication rule so: (1/214)(1/214) = 1/45796

(b) You meet 31 new friends; what is the probability that at least one of these new friends was born on a Friday the 13th?

I cant figure this out. If they were disjoint then I could just use the addition rule, but they aren't so I am very confused.

Any help will be greatly appreciated.