Question

A and B are events such that P(A+B)=3/4, P(AB)=1/4 and P(A')=2/3. What is P(B)?

Answer 1

Firstly find P(A)..

P(A) = 1 - P(A')

can you find P(A)..??

Answer 2

yup...then??

Answer 3

Tell me what is it..

Answer 4

1/3

Answer 5

Use:

\[\large \color{green}{P(A + B) = P(A) + P(B) - P(AB)}\]

Answer 6

p(a)=1-2/3=1/3
p(b)=p(a+b)+p(ab)-p(a)=3/4 +1/4 - 1/3=2/3

Answer 7

@matricked why are you giving solution in one go???

Answer 8

Don't look at the solution do it yourself @Mitul

Answer 9

thank u....i was confused if P(A U B) and P(A+B) were same...@waterineyes thank u very much

Answer 10

See:

P(A or B) = P(A+B)

P(A and B) = P(A*B) = P(AB)

\(\color{green}{AND}\) represents Multiplication..
\(\color{green}{OR}\) represents Addition..

Answer 11

yup :)