Question

19. Which of the following is the formula of permutation and combination? A. $nP_r = \frac{n!}{r!}$ and $nC_r = \frac{n!}{r!}$ B. $rP_n = \frac{n!}{n!}$ and $nC_r = \frac{n!}{(n-r)!(r!)}$ C. $nP_r = \frac{n!}{(n-r)!}$ and $rC_n = \frac{n!}{r}$ D. $nP_r = \frac{n!}{(n-r)!}$ and $nC_r = \frac{n!}{(n-r)!(r!)}$

          19. Which of the following is the formula of permutation and combination?
A. $nP_r = \frac{n!}{r!}$ and $nC_r = \frac{n!}{r!}$
B. $rP_n = \frac{n!}{n!}$ and $nC_r = \frac{n!}{(n-r)!(r!)}$
C. $nP_r = \frac{n!}{(n-r)!}$ and $rC_n = \frac{n!}{r}$
D. $nP_r = \frac{n!}{(n-r)!}$ and $nC_r = \frac{n!}{(n-r)!(r!)}$

19. Which of the following is the formula of permutation and combination?
A. nPr = (n!)/(r!) and nCr = (n!)/(r!)
B. rPn = (n!)/(n!) and nCr = (n!)/((n-r)!(r!))
C. nPr = (n!)/((n-r)!) and rCn = (n!)/(r)
D. nPr = (n!)/((n-r)!) and nCr = (n!)/((n-r)!(r!))

Added by Rocio R.

Elementary Statistics a Step by Step Approach

Allan G. Bluman 9th Edition

Instant Answer

Solved by Expert Pritesh Ranjan

Step 1

The formula for combination is nC = n! / (r!(n-r)!), where n is the total number of items and r is the number of items chosen. Looking at the options: A. nP = n! and nC = n! / (n-r)! - This is incorrect because it does not include the division by r! in the Show more…

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19. Which of the following is the formula for permutation and combination? A. nP = n! and nC = n! / (n-r)! B. nPr = n! / (n-r)! and nCr = n! / (r!(n-r)!) C. nP = n! and rCn = n! / (n-r)! D. nP = n! and nCr = n! / (n-r)!(r!)