Question

There are 50 runners in a race. How many ways can the runners finish first, second, and third?

Answer 1

Number of ways can the runners finish first, second, and third is 1,17,600 .

Step-by-step explanation:

Permutation is the act of arranging the members of a set into a sequence or order, or, if the set is already ordered, rearranging (reordering) its elements—a process called permuting. For example, written as tuples, there are six permutations of the set {1,2,3}, namely: (1,2,3), (1,3,2), (2,1,3), (2,3,1), (3,1,2), and (3,2,1). Formula of Permutation is : $P(n,r) = \frac{n!}{(n-r)!}$ where n is the number of things to choose from,  and we choose r of them,  no repetitions,  order matters. Here , n = 50 , r= 3

⇒ $P(n,r) = \frac{n!}{(n-r)!}$

⇒ $P(50,3) = \frac{50!}{(50-3)!} = \frac{50(49)(48)47!}{47!}$

⇒ $P(50,3) = 50(49)(48)$

⇒ $P(50,3) = 1,17,600$

∴ Number of ways can the runners finish first, second, and third is 1,17,600 .