Multiple choice general knowledge math & puzzles

4) The probabilities that a husband and wife will be alive 20 years from now are 0.8 and 0.9 respectively. Find the probability that in 20 years at least one will be alive.

  1. 0.26

  2. 0.76

  3. 0.86

  4. 0.36

  5. 0.98

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The probability that at least one is alive is 1 minus the probability that both are dead. The probability the husband dies is 0.2 (1-0.8) and the wife dies is 0.1 (1-0.9). 1 - (0.2 * 0.1) = 1 - 0.02 = 0.98.