Answer :
Answer: [tex]\dfrac{1}{15}[/tex]
Step-by-step explanation:
Given : Total rolls of film in the box = 10
Defective rolls =3
Probability of selecting first defective roll = [tex]\dfrac{\text{Number of bad rolls}}{\text{Total rolls}}[/tex]
[tex]=\dfrac{3}{10}[/tex]
Now , total rolls left = 9
Total defective rolls left = 2
Probability of selecting second defective roll = [tex]\dfrac{\text{Number of bad rolls}}{\text{Total rolls}}[/tex]
[tex]=\dfrac{2}{9}[/tex]
Now , the probability of selecting a defective roll followed by another defective roll = [tex]\dfrac{3}{10}\times\dfrac{2}{9}=\dfrac{1}{15}[/tex]
Hence, the probability of selecting a defective roll followed by another defective roll is [tex]\dfrac{1}{15}[/tex] .