Explanation
Step 1: Determine individual probabilities from the given odds
The relation between odds in favor (a:b) and probability is given by P(E)=a+ba.
Step 2: Apply the addition theorem of probability
According to set theory and probability:
P(A∪B)=P(A)+P(B)−P(A∩B)
Substitute the known values into the equation:
43=32+P(B)−P(A∩B)
Rearranging the formula to express P(B) in terms of P(A∩B):
P(B)=43−32+P(A∩B)
P(B)=129−8+P(A∩B)
P(B)=121+P(A∩B)— (Equation 1)
Step 3: Establish constraints to find the minimum and maximum values
The intersection of two sets, A∩B, must satisfy standard set theory limits:
0≤P(A∩B)≤min(P(A),P(B))
Additionally, since P(A∪B)=43, the maximum possible value for any component probability set bounded within this union cannot exceed the union value itself.
For the Minimum Value of P(B):
The smallest possible value for the intersection probability is P(A∩B)=0 (when events A and B are mutually exclusive).
Substituting P(A∩B)=0 into Equation 1:
P(B)min=121+0=121
For the Maximum Value of P(B):
The largest value occurs when B expands as much as possible within the sample space constraints. Since the maximum upper bound of any probability is 1 and it cannot exceed the boundaries defined by standard logic, we check the condition for the intersection maximum bound:
P(A∩B)≤P(A)
P(A∩B)≤32
Also, the maximum probability value for P(A∪B) cannot exceed the sum of individual subsets if they overlap completely, meaning B can completely encapsulate the remainder of the union space up to P(A∪B)=43.
Thus, the absolute maximum probability for event B cannot exceed the overall probability of the union of both events:
P(B)≤P(A∪B)
P(B)max=43
Step 4: Combine the inequalities
Combining both the minimum and maximum boundary values calculated above:
121≤P(B)≤43
Correct Answer: A) 121≤P(B)≤43