1 .
What is the minimum number of people needed so that we can guarantee that at least three of them
have the same birthday? (We ignore leap years; thus, a year has 365 days.)
(a)
$365^2$
(b)
$2 \cdot 365 + 1$
(c)
$2 \cdot 365$
(d)
$365^2 + 1$