If p is the probability that a man aged x will die in a year,  then the probability that out of n men A1,A2,…,An each  aged x,A1 will die in an year and be the first to die is

Let the probability that a man aged x dies in a year p. Thus, the probability that a man aged x does not die in a year is 1 - p . The probability that all n men aged x do not die in a year is (1 - p)". Therefore, the probability that at least one man diesin a year is 1 - (1 - p)". The probability that out of n men, A1 dies first is1n. Since this event is independent of the eventthat at least one man dies in a year ,the probability that A1  dies in the year and he is the first one to die is 1/n1−(1−p)n