Counting_Methods3(1&2)

Counting_Methods3(1&2) - the box? Counting methods...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Counting methods 3 Three towns A, B and C are connected by a number of roads. There are three from A to B and two from B to C B A C
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Counting methods 3 A B C 2 ways A B C 2 ways A B C 2 ways
Background image of page 2
Counting methods 3 There are 6 ways of going from A to B to C i.e. 3 × 2 = 6 ways of making the trip A B C 2 ways A B C 2 ways A B C 2 ways
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Counting methods 3 Position 1 Position 2 Position 3 How many ways can 3 balls be placed in a row? FACTORIAL
Background image of page 4
Counting methods 3 With blue in the first position With red in the first position With green in the first position
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Counting methods 3 The number of ways = 3 × 2 × 1 = 6 ways If 4 balls were to be placed in a row the total number of ways would be 4 × 3 × 2 × 1 = 24 ways Note 3! = 3 × 2 × 1 4! = 4 × 3 × 2 × 1
Background image of page 6
Counting methods 3 6 4 2 5 3 1 How many ways can 4 rabbits be selected from
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: the box? Counting methods 3 Order does not matter and so all of the following are considered to be the same 2 3 1 3 2 2 2 3 3 3 3 2 2 1 1 1 1 1 Counting methods 3 Position 1 Position 2 Position 3 The first position can be filled in 6 ways, the second in 5 and the third in 4 ways. Thus there are 6 5 4 ways of placing the rabbits in a row of three But there are 3 2 1 ways of arranging a particular three rabbits in a row. Therefore the number of ways the rabbits can be chosen = 20 1 2 3 4 5 6 = Counting methods 3 123 124 125 126 134 135 136 145 146 156 234 235 236 245 246 256 345 346 356 456 The possible selections are as shown...
View Full Document

Page1 / 10

Counting_Methods3(1&2) - the box? Counting methods...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online