High School

At a competition with 7 runners, 2 medals are awarded for first and second place. Each medal is different. How many ways are there to award the medals?

a) 42
b) 49
c) 56
d) 63

Answer :

Final answer:

There are 42 ways to award the medals at the competition. (Option A)

Explanation:

Given:

Number of runners: 7

Number of medals to be awarded: 2

Calculate the number of permutations:

To determine the number of ways to award the medals, we use the concept of permutations. Permutations represent the number of ways to arrange objects in a specific order.

We use the formula for permutations: Pₙᵣ = n! / (n - r)!, where n is the total number of objects and r is the number of objects being arranged.

Substitute the given values:

For this problem, n = 7 (number of runners) and r = 2 (number of medals to be awarded).

So, we plug these values into the permutation formula: P₇₂ = 7! / (7 - 2)!.

Calculate the factorial:

Calculate the factorials in the formula. 7! = 7 × 6 × 5 × 4 × 3 × 2 × 1 and (7 - 2)! = 5! = 5 × 4 × 3 × 2 × 1.

Perform the division:

Divide 7! by (7 - 2)! to get the number of permutations of 7 objects taken 2 at a time.

Calculate the result:

P₇₂ = 7! / (7 - 2)! = (7 × 6 × 5 × 4 × 3 × 2 × 1) / (5 × 4 × 3 × 2 × 1) = 7 × 6 = 42.

Therefore, there are 42 ways to award the medals at the competition, as determined by the permutation of 7 runners for 2 distinct medals. (Option A)