2.Sequential Experiments

2. I.

Tree Diagrams

Ex 2.1 )probability of choosing aresistor from machine Ba that is not acceptable

A•BIA 0.24 PCBIAI

Po?!

')B,N•B,N0.06

A•132A 0.36

•-

132-0.1

root

N.BZN 0.04 →PCBs N)=PCBs ]PINI Be]

/Bz

4A•133A 0.18 =0.04

branch I"

N•133N O.12

node fenditional "

probability leaf

Ex 2.3 )Monty Hall

first chosen door :I

H;:the event that the car is hidden behind door i

Ri :the event that Monty opens door ithat hides agoat

Rz :G£

IfHI I123 :GII

Hz -1 Rs :C

Is )zz

-3

Hz -1 R2 :c

(switch >(Do not switch )

2. 2

.Counting methods

*k.permutations of ndistinguishable objects f- Sampling without replacement )

nPk =(n)k =n(n-1) Cn-21 . -Cn -KH )=I

@

-k)!

*k-combinations of ndistinguishable objects

nor ==HIT =µi=n !)