Probability — Class 12 Maths Solution

ncert misc SA NCERT,Misc,Q.19,Page.584
Question

If $A$ and $B$ are any two events such that
$P(A) + P(B) - P(A{\rm{ and }}B) = P(A),$ then

(A) $P(B|A) = 1$

(B) $P(A|B) = 1$

(C) $P(B|A) = 0$

(D) $P(A|B) = 0$

Step-by-step Solution

Option B is correct

$P(A) + P(B) - P(A \cap B) = P(A)$

$\Rightarrow P(B) - P(A \cap B) = 0$

$\Rightarrow P(A \cap B) = P(B) \Rightarrow \cfrac{{P(A \cap B)}}{{P(B)}} = 1 \Rightarrow P(A/B) = 1$

NCERT & Exemplar solution for CBSE Class 12 Mathematics, Probability. Curated by Sachin Sharma. Free for all students.