If one event can occur in *m*
ways and a second can occur in *n* ways, the pair of events can occur in *mn*
ways.

__Example 1:__

There are 4 roads from Carleton to Washington
and 6 roads from Washington
to Hareton. How many Carleton-Washington-Hareton routes are possible?

Answer: Each
of the 4 roads from Carleton to Washington
has 6 different choices. So, the total number of routes is 4 x 6 = 24

__Example
2:__

A baseball team has 6 pitchers and 3 catchers. How many different
pitcher-catcher combination are there?

Answer: For
each of the 6 pitchers there are 3 catchers; so there are 18 combinations.

__Example 3:__

In how many ways can 10 multiple-choice questions be answered if each question
has 4 choices and each question is answered? if 2
questions are left unanswered?

Answer: If
all questions were answered then there are 10 x 4 = 40 ways; if 2 questions were
unanswered then there are 8 x 4 = 32 ways.

**Next : Permutation**

**Previous : Probability Scale **