A particular automatic sprinkler system has two different types of activation devices for each sprinkler head. One type has a reliability of 0.89; that is, the probability that it will activate the sprinkler when it should is 0.89. The other type, which operates independently of the first type, has a reliability of 0.79. If either device is triggered, the sprinkler will activate. Suppose a fire starts near a sprinkler head. What is the probability that the sprinkler head will be activated

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.