UGC NET Questions (Paper – 1)

Conditional probability is written using a vertical bar “|”. P(A|B) means “the probability of A given that B has already occurred,” i.e., the sample space is restricted to outcomes where B happens.

Option A:
P(A ∩ B) is the probability that both A and B occur together (intersection). It does not represent “given B occurred,” so it is not conditional probability.

Option B:
P(A ∪ B) is the probability that A or B (or both) occur (union). It does not express “given B,” so it is not the required notation.

Option C:
P(A|B) is correct because it explicitly means “probability of A given B.” This is the standard notation for conditional probability in probability theory and statistics.

Option D:
P(B|A) means “probability of B given A,” which reverses the condition. The question asks for “A given B,” so this is not correct.