The probability that a 50 year old man will be alive in 10 years is 0.78 , and the probability that his 45 year old wife will be alive is 0.91 . Determine the probability that in 10 years:

Question

a. both will be alive

b. at least one will be alive (HINT: what is the complement to the event that at least one is alive?)

c. only the wife will be alive

Answer 1

a. 0.78 * 0.91

b. both dead = (1 - .78)(1 - .91)
so at least one alive = 1 - (1 - .78)(1 - .91)

c. her alive * him dead = .91 (1 - .78)

Answer 2

.... and it looks like my wife and I are long gone.