A widget company produces 25 widgets a day, 5 of which are defective. Find the probability of selecting 5 widgets from the 25 produced where none are defective.

A. [tex]\frac{1}{3125}[/tex]
B. [tex]\frac{1}{5}[/tex]
C. [tex]\frac{2584}{8855}[/tex]
D. [tex]\frac{1}{10626}[/tex]



Answer :

To find the probability of selecting 5 widgets from the 25 produced, where none are defective, we need to approach this problem step by step.

1. Total Number of Widgets: The company produces 25 widgets each day.

2. Defective Widgets: Out of these 25 widgets, 5 are defective.

3. Selecting Widgets: We need to calculate the probability of selecting 5 widgets where none are defective.

Step 1: Calculate the Total Number of Ways to Select 5 Widgets from 25

To find the total number of ways to select 5 widgets from 25, we use the combination formula:
[tex]\[ \binom{25}{5} = \frac{25!}{5!(25-5)!} \][/tex]

According to our result:
[tex]\[ \binom{25}{5} = 53130 \][/tex]

Step 2: Calculate the Number of Ways to Select 5 Non-defective Widgets

Since there are 20 non-defective widgets (25 total widgets minus 5 defective widgets), we use the combination formula to find the number of ways to select 5 non-defective widgets from these 20:
[tex]\[ \binom{20}{5} = \frac{20!}{5!(20-5)!} \][/tex]

According to our result:
[tex]\[ \binom{20}{5} = 15504 \][/tex]

Step 3: Calculate the Probability

The probability of selecting 5 widgets and finding none defective is the ratio of the number of ways to select 5 non-defective widgets to the total number of ways to select 5 widgets from the 25:
[tex]\[ \text{Probability} = \frac{\binom{20}{5}}{\binom{25}{5}} = \frac{15504}{53130} \][/tex]

Step 4: Simplify the Fraction

When simplified, the fraction [tex]\(\frac{15504}{53130}\)[/tex] reduces to:
[tex]\[ \frac{2584}{8855} \][/tex]

Step 5: Conclusion

Thus, the probability of selecting 5 widgets from the 25 produced where none are defective is:

[tex]\[ \boxed{\frac{2584}{8855}} \][/tex]

Therefore, the correct answer is C. [tex]\(\frac{2584}{8855}\)[/tex].