Question

The probability of a machine producing a defective bulb is $0.1$ if $10$ bulbs are taken from the bulbs produced by the machine, what is the probability that
a) No bulb will be defective
b) $3$ bulbs will be defective

Answer 1

Probability that it is defective=0.1

10 bulbs are taken

1) Probability that no bulb is defective=${0.9}^{10}$

2)Probability that 3 bulbs are defective=${{10}_C}_3\times {0.1}^3\times {0.9}^7$