Questions: Combination or Permutation Question:
a skating competition of 17 skaters, how many ways can you pick the best 2 skaters if you have to pick the exact order they place?
Combination or Permutation Question:
a skating competition of 17 skaters, how many ways can you pick the best 2 skaters if you have to pick the exact order they place?
Solution
Solution Steps
To solve this problem, we need to determine the number of permutations of 2 skaters from a group of 17. Since the order in which the skaters are picked matters, we use permutations rather than combinations. The formula for permutations is given by \( P(n, r) = \frac{n!}{(n-r)!} \), where \( n \) is the total number of items to choose from, and \( r \) is the number of items to choose.
Step 1: Identify the Problem Type
The problem requires finding the number of ways to select and order 2 skaters from a group of 17. Since the order matters, this is a permutation problem.
Step 2: Apply the Permutation Formula
The formula for permutations is given by:
\[
P(n, r) = \frac{n!}{(n-r)!}
\]
where \( n = 17 \) is the total number of skaters, and \( r = 2 \) is the number of skaters to be selected.
Step 3: Calculate the Permutations
Substitute the values into the permutation formula:
\[
P(17, 2) = \frac{17!}{(17-2)!} = \frac{17!}{15!}
\]
This simplifies to:
\[
P(17, 2) = 17 \times 16 = 272
\]
Final Answer
The number of ways to pick and order the best 2 skaters from 17 is \(\boxed{272}\).