Posted by Jen on .
Consider the Venn diagram below. The numbers in the regions of the circle indicate the number of items that belong to that region.
(2 intersecting circles A & B, where A part is 50, B part is 110, and the intersecting part is 40)
Determine:
n(A)
n(B)
P(A)
P(B)
P(AB)
P(BA)

MathCan you help me Damon or Reiny? 
Reiny,
counting all the numbers in A I see n(A) = 90
n(B)=150
total is 200 , P(A) = 90/200 = 9/20
P(B) = 150/200 = 3/4
P(AB) is a conditional probability and is defined as
P(A∩B/P(B)
= (40/200) / (3/4) = 4/15
find P(BA) the same way 
MathCan you help me Damon or Reiny? 
Reiny,
missed a bracket ...
P(AB) is a conditional probability and is defined as
P(A∩B) / P(B)