Probability Explanation And Exercises Worksheet Page 15
ADVERTISEMENT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37Table 1. Six Possible Orders.
Number
First
Second
Third
1
red
yellow
green
2
red
green
yellow
3
yellow
red
green
4
yellow
green
red
5
green
red
yellow
6
green
yellow
red
The formula for the number of orders is shown below.
Number of orders = n!
where n is the number of pieces to be picked up. The symbol “!” stands for
factorial. Some examples are:
3! = 3 x 2 x 1 = 6
4! = 4 x 3 x 2 x 1 = 24
5! = 5 x 4 x 3 x 2 x 1 = 120
This means that if there were 5 pieces of candy to be picked up, they could be
picked up in any of 5! = 120 orders.
Multiplication Rule
Imagine a small restaurant whose menu has 3 soups, 6 entrées, and 4 desserts. How
many possible meals are there? The answer is calculated by multiplying the
numbers to get 3 x 6 x 4 = 72. You can think of it as first there is a choice among 3
soups. Then, for each of these choices there is a choice among 6 entrées resulting
in 3 x 6 = 18 possibilities. Then, for each of these 18 possibilities there are 4
possible desserts yielding 18 x 4 = 72 total possibilities.
Permutations
Suppose that there were four pieces of candy (red, yellow, green, and brown) and
you were only going to pick up exactly two pieces. How many ways are there of
199
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education