A bingo card is the basic unit of play in a bingo game. Printed on paper or
generated by computer, all bingo cards contain five columns of five numbers
between 1 and 75.
From left to right, each column is headed by a letter: B, I, N, G or O. The
center spot (the third number down in the "N" column) is always given to the
player, and often is marked "Free."
A generic bingo card could look like
this:
B
I
N
G
O
14
16
44
59
62
3
20
34
55
70
11
30
free
46
74
8
24
40
50
67
5
17
36
54
72
All
bingo cards are generated randomly and are valid for one game only. At the start of a game, all players
receive new bingo cards every game.
One more thing: A bingo card's "B" column may only contain numbers
from 1 to 15; the "I" column may only contain 16 to 30; the "N" column 31 to 45,
the "G" column 46 to 60, and the "O" column 61-75. In other words...