We know that the average life of a light bulb is 10,000 hours. There are 12 light bulbs in a classroom. In order for a class to be held in the room, 9 or more light bulbs must be working. Each light bulb works independently of the other light bulbs in a classroom.
A) Name the distribution of a light bulb's life and specify parameters.
B) What is the probability that a single light bulb works 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?
D) Given a light bulb operates no more than 15,000 hours, what's the probability that it breaks before 5,000 hours? E)Assuming that all light bulbs in a room were installed at the same time, what is the probability that a class can be held in that room after 10,000 hours of light bulbs' operation?