We know that the average life of a light bulb is 10,000 hours.There are 12 lightbulbs in a classroom. In order for a class to be held in the room,9 or more lightbulbs must be working. Each light bulb works independently of the other light bulbs in a classroom.
a) Name the distribution of a lightbulb's lifeand specify the parameters.
b) What is the probability that a single lightbulbworks for over 10,000 hours?
c) Given a light bulb has already operated for 5,000 hours, what's the probability that it will operate more than 15,000 hours total?
d) Given a light bulb operates no more than 15,000 hours, what's the probability that it breaks before 5000 hours?
e) Assuming that all the light bulbs in a room were installed at the same time, what is the probability that a class can beheld in that room after 10,000 hours of the light bulbs' operation?