12.5 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 =56 5

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

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 11 c =462 5

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 10 c =210 4

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 10 c =120 5

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 9 c =126 4