Question

for every 1000 bulbs manufactured by
a factory 5 bulbs are
defective
A customer
buys one bulb
from a shop without
Testing it. probability
of
D defective
2 Non defective ​

Answer 1

The total observation =1000

The number of defective bulbs = 5

The Probability of defective bulbs= 5/1000

= 1/200=0.005

And the Probability of non defective bulbs

= (1000-5)/1000

=995/1000

=0.995

The sum of the Probabilities= 0.995+0.005

= 1

Hope this helps you friend