Answer:
Latter C.
Step-by-step explanation:
..............................
Answer:
1/12
Step-by-step explanation:
Answer: a. 0.05
b. 0.40
c. 0.85
Step-by-step explanation:
Let F= Event that a certain motorist must stop at the first signal.
S = Event that a certain motorist must stop at the second signal.
As per given,
P(F) = 0.45 , P(S) = 0.5 and P(F or S) = 0.9
a. Using general probability formula:
P(F and S) =P(F) + P(S)- P(F or S)
= 0.45+0.5-0.9
= 0.05
∴ the probability that he must stop at both signals = 0.05
b. Required probability = P(F but (not s)) = P(F) - P(F and S)
= 0.45-0.05= 0.40
∴ the probability that he must stop at the first signal but not at the second one =0.40
c. Required probability = P(exactly one)= P(F or S) - P(F and S)
= 0.9-0.05
= 0.85
∴ the probability that he must stop at exactly one signal = 0.85
