Basic counting/combinatorics question Consider a set of 100 airline passengers numbered 1 to 100. How many ways to seat them into 100 seats such that even numbered passengers only go to even numbered seats and odd num...--prophetes.ai

Basic counting/combinatorics question Consider a set of 100 airline passengers numbered 1 to 100. How many ways to seat them into 100 seats such that even numbered passengers only go to even numbered seats and odd numbered passengers only go to odd numbered seats.

By permutation and Rule of product we simply have

$$N=50!\cdot50!$$