Arrangement of Items

Arrange 5 boxes (A,B,C,D,E) in as many ways as possible. Each time you may select 3 boxes. How many different ways are there?

 

立方體: A 立方體: B 立方體: C 立方體: D 立方體: E
 

 

 

 


Answer: Totally 60 ways. They are:

立方體: C
立方體: A 立方體: B
立方體: A 立方體: B 立方體: D
立方體: A 立方體: B 立方體: E
 

 

 

 

 

 

 

 

 

 


                    … AND SO ON…

 

 

There may be too many choices to count. But we may do it in a systemic way using a table. This table may also be written as:

 

1ST BOX
5
choices

2ND BOX
4
choices

3RD BOX
3
choices

A

B

C

D

E

C

B

D

E

D

B

C

E

E

B

C

D

B

A

C

D

E

C

A

D

E

D

A

C

E

E

A

C

D

C

A

B

D

E

B

A

D

E

D

A

B

E

E

A

B

D

D

A

B

C

E

B

A

C

E

C

A

B

E

E

A

B

C

E

A

B

C

D

B

A

C

D

C

A

B

D

D

A

B

C

 

FINAL ANSWER:

The 60 choices, listed in a table, are:

1ST BOX
5
choices

2ND BOX
4
choices

3RD BOX
3
choices

A

B

C

A

B

D

A

B

E

A

C

B

A

C

D

A

C

E

A

D

B

A

D

C

A

D

E

A

E

B

A

E

C

A

E

D

B

A

C

B

A

D

B

A

E

B

C

A

B

C

D

B

C

E

B

D

A

B

D

C

B

D

E

B

E

A

B

E

C

B

E

D

C

A

B

C

A

D

C

A

E

C

B

A

C

B

D

C

B

E

C

D

A

C

D

B

C

D

E

C

E

A

C

E

B

C

E

D

D

A

B

D

A

C

D

A

E

D

B

A

D

B

C

D

B

E

D

C

A

D

C

B

D

C

E

D

E

A

D

E

B

D

E

C

E

A

B

E

A

C

E

A

D

E

B

A

E

B

C

E

B

D

E

C

A

E

C

B

E

C

D

E

D

A

E

D

B

E

D

C