Use combinations to solve the following problem. From a class of 17 students, the teacher needs 5 students to work in the student store during lunch. How many ways can the teacher make the schedule with 5 different students?(1 point)

Responses

75
75

1
1

6,188
6,188

742,560

1 answer

To find the number of ways to choose 5 students from a class of 17 students, we can use the combination formula, which is represented as:

\[ \binom{n}{r} = \frac{n!}{r!(n-r)!} \]

where \( n \) is the total number of students (17 in this case), \( r \) is the number of students to choose (5 in this case), and \( ! \) denotes factorial.

Using this formula:

\[ \binom{17}{5} = \frac{17!}{5!(17-5)!} = \frac{17!}{5! \cdot 12!} \]

Calculating this step-by-step:

  1. Calculate \( 17! \) up to \( 12! \):

\[ \frac{17 \times 16 \times 15 \times 14 \times 13 \times 12!}{5! \times 12!} \]

  1. The \( 12! \) terms cancel out:

\[ \frac{17 \times 16 \times 15 \times 14 \times 13}{5!} \]

  1. Now calculate \( 5! = 5 \times 4 \times 3 \times 2 \times 1 = 120 \).

  2. Now compute the product of the numerator:

\[ 17 \times 16 = 272, \] \[ 272 \times 15 = 4080, \] \[ 4080 \times 14 = 57120, \] \[ 57120 \times 13 = 742560. \]

  1. Finally, divide by \( 120 \):

\[ \frac{742560}{120} = 6188. \]

So the number of ways to choose 5 students from a class of 17 is:

\[ \binom{17}{5} = 6188. \]

Therefore, the correct answer is 6,188.