CBSE 2026 · Region 1 · Set 1 · Q19 · 1 mark
Assertion (A) : In an experiment of throwing an unbiased die, the probability of getting a prime number given that number appearing on the die being odd is $\displaystyle \frac{2}{3}$.
Reason (R) : For any two events A and $\displaystyle \mathrm{B}, \mathrm{P}(\mathrm{A} \mid \mathrm{B})=\frac{\mathrm{P}(\mathrm{A} \cup \mathrm{B})}{\mathrm{P}(\mathrm{B})}$
Official answer
From CBSE’s own marking scheme for this paper.
(C)
Assertion (A) is true and Reason (R) is false.
ProbabilityConditional ProbabilityAnalyseassertion_reasonmedium
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CBSE Class 12 Mathematics past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.