BITSAT2012MathematicsProbabilityActual
The probability of simultaneous occurrence of atleast one of two events A and B is p . If the probability that exactly one of A, B occurs is q then P (A^ )+P (B^ ) is equal to
Options
- A2-2 p+q
- B2+2 p-q
- C3-3 p+q
- D2-p+q
Correct answer
A. 2-2 p+q
Step-by-step solution
Since, P( exactly one of A, B occurs )=q . P(A B)-P(A B)=q p-P(A B)=q P(A B)=p-q 1-P (A^ B^ )=p-q P (A^ B^ )=1-p+q P (A^ )+P (B^ )-P (A^ B^ )=1-p+q P (A^ )+P (B^ )=(1-p+q)+[1-P(A B)]=(1-p+q)+(1-p)=2-2 p+q