Answer:
a) Therefore, the probability is P=0.98.
b) Therefore, the probability is P=0.02.
c) Therefore, the probability is P=0.72.
d) Therefore, the probability is P=0.18.
Step-by-step explanation:
We know that: One type has a reliability of 0.9; that is, the probability that it will activate the sprinkler when it should is 0.9.
The other type, which operates independently of the first type, has a reliability of 0.8.
We get
a) We calculate the probability that the sprinkler head will be activated.
Therefore, the probability is P=0.98.
b) We calculate the probability that the sprinkler head will not be activated.
Therefore, the probability is P=0.02.
c) We calculate the probability that both activation devices will work properly.
Therefore, the probability is P=0.72.
d) We calculate the probability that only the device with reliability 0.9 will work properly.
Therefore, the probability is P=0.18.