If the probability that a fulurorescent light has a useful life of a least 800 hours is 0.9 find the probability that among 20 such lights at least 2 will not have a useful life of at least 800 hours. [ Given `(0.9) = 0.1348 ] `

If the probability that a flourescent light has a useful life of atleast 800 hours is 0.9,find the probabilities that among 20 such lights atleast 2 will not have a useful life of atleast 800 hours.

If the probability that fluoreacent light has a useful life of at least 600 hours is 0.9 find the probabilites that among 12 such lights at least 11 will have a useful life of at least 600 hours

If the probability that fluoreacent light has a useful life of at least 600 hours is 0.9 find the probabilites that among 12 such lights at least 2 will not have a useful of at least 600 hours

If the probability that fluoreacent light has a useful life of at least 600 hours is 0.9 find the probabilites that among 12 such lights exactly 10 will have a usefull life of at least 600 hours

If the probability that a fluorescent ligth has a usefule life of at least 600 hours is 0.9 , find the probabilities that amond 12 such lights. (i) exactly 10 will have a useful life of at least 600 hours , (ii) at least 11 will have a useful life of at least 600 hours , (iii) at least 2 will not have a useful life of at least 600 hours