Question

if A and B are two events p(A) =1/4,p(b)=1/2p(A,B)=1/8. Find (i) p(a or b) (ii) p(not a and not b) ​

Answer 1

Answer:

Given P(A)=  

2

1

​

P(B)=  

4

1

​

⟹P(B)=  

4

2

​

=  

2

1

​

 

P(A∩B)=  

8

1

​

 

P(A∪B)=P(A)+P(B)−P(A∩B)=  

4

1

​

+  

2

1

​

−  

8

1

​

=  

8

2+4−1

​

=  

8

5

​

 

P(not A and not B)=P(A  

′

∩B  

′

)=1−P(A∪B)=1−  

8

5

​

=  

8

8−5

​

=  

8

3

​

Step-by-step explanation: