Answer:
We use this formula:
n! / r! * (n-r)!
where we are choosing "r" elements from a larger set of "n" elements
40! / 20! * (40-20)! =
40! / 20! * 20! =
40*39*38*37*36*35*... 20! / (20! * 20!) =
40*39*38*37*36*35*34*33*32*31*30*29*28*27*26*25*24*23*22*21*20! ALL divided by (20! * 20!) =
40*39*38*37*36*35*34*33*32*31*30*29*28*27*26*25*24*23*22*21 / 20!
=335,367,096,786,357,000,000,000,000,000 / 2,432,902,008,176,640,000
which equals
137,846,528,820 totally different ways
Step-by-step explanation:
