a family consists of 3 children.if 1 child is selected at random ,what is the probability of getting a)2 boys b)atleast 1 girl c)no boys.

Asked by  | 27th Oct, 2012, 11:51: AM

Expert Answer:

Answer : Given : a family consists of 3 children.
To find :The probability if 1 child is selected at random  is a)2 boys b)atleast 1 girl c)no boys.
 
Let B denote a boy and G a girl
 
Each birth can be either a B or G so 2 ways and since 4 events or birth,

the sample space is of size = 2 x 2 x 2 = 8

(a) There are exactly two boys

Events with exactly 2 boys are: {BBG, BGB, GBB} = 3 in set

P[ exactly 2 boys] = 3/8

(b) Atleast 1 girl.

Event all children are girls:{GBB,BGB,BBG,GGB,GBG,BGG,GGG}

Pr[all girls] =7/8

c) No boy

P[no boy] = {GGG} =1/8

The sample space is : { BBB,BBG,BGB,GBB,BGG,GBG,GGB,GGG}

Answered by  | 27th Oct, 2012, 06:44: PM

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