The probability that a bulb produced by a factory will fuse after 6 months of use is find the probability that out of 5 such bulbs
(i) none will fuse after 6 months of use
(ii) at least one will fuse after 6 months of use

(i) The probability that the bulb will fuse
The probability that the bulb will not fuse
Using Bernoulli’s we have,

Probability that none will fuse

(ii) The probability that the bulb will fuse
The probability that the bulb will not fuse
Using Bernoulli’s we have,

Probability that at least one will fuse