A pianist plans to play 5=pieces at a recital from her repertoire of 20 pieces, and is carefully considering which song to play first, second etc. to create a good flow. How many different recital programs are possible?

2432902008176640000 programs are possible using 20 distinct (different) songs.

Step-by-step explanation:

There are 20 choices for the first song, 19 choices for the second, ...1 song for the last for a total of

N = 20*19*18*...*3*2*1 = 20!= 2432902008176640000  programs

The number 20! is the number of permutations for 20 distinct objects put in order.

20! is pronounced as 20 factorial.

Example: factorial of 5 is 5*4*3*2*1 = 120

20*19*18*17*16=1 860 480 different programs

Step-by-step explanation:

So there are 20 pieces total and each of them can be first.

Each of residual 19 can be the second

Each of residual of 18 can be the third

Each of residual 17 can be the fourth

Each of residual 16  can be the fifth

Total amont of possible different programs ( the order of the pieces matters)

is :  20*19*18*17*16=1 860 480 different programs