1. Combinations Practical Applications
When we hear about committees or
when a question says ‘how many different ways’ we use combinations
Think about people standing on one side of a room and the ones we want
have to walk over to the other side
e.g 1 How many ways can a committee of 5 people be chosen from a group of 8 8 c 5
=56

2. e.g 2 How many ways can 3 books be chosen from a shelve of 10
=120

3. e.g 2 How many ways can a team of 5 players be chosen from a squad of 11
(i) if there are no restrictions
(ii) If a certain member must be on the team
(iii) If a certain player cannot play
(iv) If one player cannot player and one must play c 11 5
=462

4. e.g 2 How many ways can a team of 5 players be chosen from a squad of 11
(ii) If a certain member must be on the team 4 c 10
=210

5. e.g 2 How many ways can a team of 5 players be chosen from a squad of 11
(iii) If a certain player cannot play 5 c 10
=120

6. e.g 2 How many ways can a team of 5 players be chosen from a squad of 11
(iv) If one player cannot player and one must play 4 c 9
=126