The probability that the persons P1 and P2 will die in a year are p and q respectively. The probability that at the end of the year only of them will be alive, is equal to
Answer & explanation
Correct answer: option 3
Let ‘A’ denotes the event that 'P1' dies in a year and ‘B’ denotes the event that 'P2' dies in a year.
Thus, required probability
$=P(\bar{A} \cap B)+P(A \cap \bar{B})$
$=P(A)+P(B)-2(A \cap B)$
$=p+q-2 p q$