Solve for n: Get Answers & Verify Results

  • Thread starter Thread starter F.B
  • Start date Start date
AI Thread Summary
The discussion revolves around solving mathematical problems, specifically focusing on permutations and probabilities. The first question involves finding n in the equation P(n,3)=6P(n-1,3), with one participant suggesting n=3. The second question addresses calculating the number of divisors for 3780, with a request for a more efficient method than brute force. The third question pertains to expected winnings in a card game, which remains unresolved, while the fourth question involves probabilities related to defective parts in manufacturing, with a participant expressing uncertainty about their calculations. Overall, the thread seeks assistance in verifying answers and clarifying concepts related to permutations and probability.
F.B
Messages
81
Reaction score
0
There are no answers given for these questions because they are based on my entire book.

Can anyone verify my answer for this question.
Solve for n

1. P(n,3)=6P(n-1,3)

When i solve for n i get 3.6.

2.Determine the number of divisors for the number 3780, using the fact that a divisor of a number is the multiplication of one or more of the factors of the number.

I know this questions is really easy. I know i can easily just use my calculator and go through every single number but is there a shorter way of doing this.

3. A game is played by drawing cards from a deck that has all face cards including aces removed. The player draws a card and is paid the face value of the card in dollars. Each play costs $5.00. how much would you expect to win or lose if you played the game 20 times?

I have no idea how to do this one.

4. A manufacting company precut tubing for lawn chairs. Management has decided that they can accept 15% of their production outside specified tolerances. The floor manager samples 10 parts per hour from the production and stops the line if 2 parts or more from the sample are outside the tolerance.
a)If the actual defect rate is 16%, what is the probability that the line would be shutdown
b)For the same defect rate, what is the probability that the line would be shut down if the sample was increased to 20 parts but production was still stopped when 2 defects were found.

For a) i did
1-[P(X=0) + P(X=1)]
I don't have time to show my work but i used the binomial experiment formula and i get 0.492 as an answer i think that's a bit high.
But i don't even know what that 15% is for.

So can anyone please help with these questions.
 
Physics news on Phys.org
what do you mean by P
Do you mena permutation as in P(n,r) = \frac{n!}{(n-r)!} in which case you are correct.

2) well i can't type it all here but i do it like this
3780 = 2 x 1890
1890 = 2 x 945
945 = 5 x 189
189 = 3 x 63
63 = 3 x 21
21 = 3 x 7
7 = 7 x 1
hope that helps
 
For P i do mean Permutation. But what about my other questions
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Back
Top