If \( \mathrm{P}(\mathrm{A})=0.4 \), \( \mathrm{P}(\mathrm{B})=0.8 \) and \( \mathrm{P}(\mathrm{B}/\mathrm{A})=0.6 \), then \( \mathrm{P}(\mathrm{A}\cup\mathrm{B})= \)
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 0.96
By the multiplication rule,
\( \displaystyle P(A\cap B)=P(A)\,P(B/A) \)
\( \displaystyle =0.4\times 0.6=0.24 \)
By the addition rule,
\( \displaystyle P(A\cup B)=P(A)+P(B)-P(A\cap B) \)
\( \displaystyle =0.4+0.8-0.24 \)
\( \displaystyle =0.96 \)
NCERT Exemplar:
Probability
