n is the number of objects you are choosing from a set of N objects.
This equation represents the number of ways to choose n objects from a set of N objects, without considering order.
To calculate n!(N-n)!, you can use the factorial function on a scientific calculator or manually calculate it by multiplying the numbers together. For N=16 and n=3, the calculation would be 3!(16-3)! = 3!13! = 6*6227020800 = 37362124800.
One example could be calculating the number of ways to choose 3 toppings from a menu of 16 toppings for a pizza. In this case, n=3 and N=16, so the calculation would be 3!(16-3)! = 6*13! = 6*6227020800 = 37362124800 possible combinations of toppings for the pizza.
Yes, there are other methods such as using the combination formula (nCr = n!/r!(n-r)!) or using a combination table. However, n!(N-n)! is the most commonly used equation for this type of calculation.