Answer:
(b) ln(33/5)
Step-by-step explanation:

Remember that in general

Answer: (bc+2ac+3ab)/(abc)
Subtract negative = add
88 + 35 = 123
The solution is 123
Answer:
97.3%
Step-by-step explanation:
Let the three bulbs be A, B and C respectively.
Let P(A) denote the probability that the first bulb will burn out
Let P(B) denote the probability that the second bulb will burn out
Let P(C) denote the probability that the third bulb will burn out
Now, we are told that Each one has a 30% probability of burning out within the month.
Thus;
P(A) = P(B) = P(C) = 30% = 0.3
Now, probability that at the end of the month at least one of the bulbs will be lit will be given as;
P(at least one bulb will be lit) = 1 - (P(A) × P(B) × P(C))
P(at least one bulb will be lit) = 1 - (0.3 × 0.3 × 0.3) = 0.973 = 97.3%