Probability sets question, P(A U B) etc?

Question

For events A and B it is known that P(A) = 2/3, P(A U B)=3/4 and
P(A n B) =5/12. Find P(B).

I make it 1/12, but my text book says 3/4! Who is right, please help!

I make it 1/2, typo above. Have done it 10 times now

Answer 1

You use

P(A U B) = P(A) + P(B) - P(A n B).

With the given info, you have

3/4 = 2/3 + P(B) - 5/12

or

9/12 = 8/12 + P(B) - 5/12

or


P(B)=1/2.

Answer 2

P(A U B) = P(A) + P(B) - P (A n B)

X = 1/2

Answer 3

P (AUB) = P(A) + P(B) -P (A n B)

3/4 = 2/3 + X - 5/12
3/4 = 3/12 + x
X = 3/4 - 1/4 = 1/2

Answer 4

P(AUB) = P(A) + P(B) - P(A n B)
3/4 = 2/3 + P(B) - 5/12
P(B) = 1/2.

Answer 5

for my section, Fundamentalist dont understand dirt about Catholicism. they in simple terms communicate about what they understand, and detect a fashion to curl Catholicism as being some evil faith. Dont examine any anti-catholic website, they are going to easily bash catholics. truly, fundamentalist whinge about the Mainline church homes and the orthodox church homes claiming to understand a lot about them. fairly, they dont understand a few thing about different branches of Christianity.

Answer 6

maybe the solution in the book is correct. try to figure it out by looking at your notes or tips from the book. if you use division in your solution, try to do multiplication.

maybe you thought U was intersection but actually it's union=or


good luck!

Answer 7

P(A U B)=P(A) + P(B) - P(AB) ==> P(B)=P(AUB)-P(A)+P(AB)

I get P(B)=1/2 from the numbers you gave. It looks like your book's wrong or those numbers are wrong