SOLUTION: A box of 20 pens has 6 that have dried out. A teacher selects 5 pens and puts then in her purse. How many ways can she select 4 good pens and 1 bad pen.

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Question 978547: A box of 20 pens has 6 that have dried out. A teacher selects 5 pens and puts then in her purse.
How many ways can she select 4 good pens and 1 bad pen.
- I started with 14 C 4 (this represents the good pens) * 6 C 1 (rep. bad pens) = 6006
Using combinations (nCr) because order doesn't matter.
I'm not sure if that is my final answer or if I have to divide by something else.
Please provide steps with brief reasoning so I can understand.
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
A box of 20 pens has 6 that have dried out. A teacher selects 5 pens and puts then in her purse.
How many ways can she select 4 good pens and 1 bad pen.
- I started with 14 C 4 (this represents the good pens) * 6 C 1 (rep. bad pens) = 6006
Using combinations (nCr) because order doesn't matter.
I'm not sure if that is my final answer or if I have to divide by something else.
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Your procedure and answer look good.
Cheers,
Stan H.
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SOLUTION: A box of 20 pens has 6 that have dried out. A teacher selects 5 pens and puts then in her purse. How many ways can she select 4 good pens and 1 bad pen. - I started with 14 C