Section 1 Addition Law of Probability
1.
There are 8 story books, 3 dictionaries and 4 comics on a book shelf. If a book is selected at
random, find the probability of getting either a story book or a comic.
2.
In a wallet, there are two $10 bank notes, s

Permutation and Combination
Section 1 Counting Principle
1.
Emily is going to choose a mobile phone service plan from either Smart Company or Global
Company.
Smart Company
Number of service plans
Global Company
6
8
In how many ways can she choose the serv

Solution
Section 1 Counting Principle
1.
By the addition rule,
the number of ways she can choose
6+8
14
2.
By the addition rule,
the number of ways to choose a cake
(5 + 1) + 3
9
3.
By the addition rule,
the number of choices she has
5+3+2
9.
By the mul