Answer:
The answer is 0.3629
Step-by-step explanation:
Let E represent the elder bridge
Let Y represent the younger bridge
Let A represent the ancient bridge
The chance that the elder bridge will collapse next year is 16%
Pr(E) = 16%
= 0.16
The chance that the elder bridge will not collapse next year is Pr(E')
Pr(E')= 1 – 0.16
= 0.84
The chance that the younger bridge will collapse next year is 4%
Pr(Y) = 4%
= 0.04
The chance that the younger bridge will not collapse next year is Pr(Y')
Pr(Y')= 1 – 0.04
= 0.96
The chance that the ancient bridge will collapse next year is 21%
Pr(A) = 21%
= 0.21
The chance that the ancient bridge will not collapse next year is Pr(A')
Pr(A')= 1 – 0.21
= 0.79
The probability that exactly one of the bridge s will collapse next year is
1 – (Pr(E') n Pr(Y') n Pr(A'))
= 1 – (0.84*0.96*0.79)
= 1 – 0.637056
= 0.362944
= 0.3629(to 4 decimal place)