Respuesta :
Solution: We are given that a basket contains three green apples and six red apples.
Three apples are randomly selected from the basket.
Now the probability of selecting first apple green is [tex] \frac{3}{9} =\frac{1}{3} [/tex]
The probability of selecting second apple green is [tex] \frac{2}{8} = \frac{1}{4} [/tex]
The probability of selecting third apple green is [tex] \frac{1}{7} [/tex]
Therefore, the probability of selecting three green apples is:
[tex] \frac{1}{3} \times\frac{1}{4} \times\frac{1}{7} =0.0119 [/tex] or 1.19%
Now how many red apples must be added to the basket in order to make the above probability smaller than 0.1%
If we add 11 red apples to the basket, then there will be 17 red apples and 3 green apples in the basket. Therefore, the probability of selecting three green apples if three apples are randomly selected is:
[tex] \frac{3}{20} \times\frac{2}{19} \times\frac{1}{18} = 0.0009 [/tex] or 0.09%
Therefore, we need to add 11 red apples to the basket to make this probability smaller than 0.1%
