Respuesta :
Answer:7980 ways
Step-by-step explanation:
When select predident:21 ways
When select secretary: 20 ways
When select treasurer: 19 ways
It is permutation
N permutation r=NPR
20permutation3=21×20×19= 7980 ways
Answer:
7980 ways
Step-by-step explanation:
Pretty simple.
we are finding variation.
Variation = N factorial/ (N-P)factorial/
N = the total number of elements we have available
P = the number of elements out of n we need to select
N = 21
P = 3
Variation = 21 factorial/(21-3)factorial = 21 factorial/ 18 factorial
Variation = 21x20x19x 18factorial/ 18 factorial
Variation = 21x20x19 = 7980 possible ways of selecting 3 positions out of a board of 21 members.
is it clear?