Page 52 - Probability Demystified

CHAPTER 2 Sample Spaces 41

15. Two dice are rolled. The probability that the sum of the spots on the
faces will be even is
3
a.
4
5
b.
6
1
c.
2
1
d.
6

Probability Sidelight

HISTORY OF DICE AND CARDS

Dice are one of the earliest known gambling devices used by humans. They
have been found in ancient Egyptian tombs and in the prehistoric caves of
people in Europe and America. The first dice were made from animal
bones—namely the astragalus or the heel bone of a hoofed animal. These
bones are very smooth and easily carved. The astragalus had only four sides
as opposed to modern cubical dice that have six sides. The astragalus was
used for fortune telling, gambling, and board games.
By 3000 B.C.E. the Egyptians had devised many board games. Ancient
tomb paintings show pharaohs playing board games, and a game similar to
today’s ‘‘Snakes and Ladders’’ was found in an Egyptian tomb dating to
1800 B.C.E. Eventually crude cubic dice evolved from the astragalus. The
dice were first made from bones, then clay, wood, and finally polished stones.
Dots were used instead of numbers since writing numbers was very
complicated at that time.
It was thought that the outcomes of rolled dice were controlled by the gods
that the people worshipped. As one story goes, the Romans incorrectly
reasoned that there were three ways to get a sum of seven when two dice are
rolled. They are 6 and 1, 5 and 2, and 4 and 3. They also reasoned incorrectly
that there were three ways to get a sum of six: 5 and 1, 4 and 2, and 3 and 3.