Answer:
A. Combination.
B. 17020
Step-by-step explanation:
A. Determination whether it is permutation or combination.
From the question given above, we were told that the student body of 185 students wants to elect two (2) representatives.
This is clearly combination because it involves a selecting process (i.e selecting 2 out of 185).
NOTE: Combination involves selecting while permutation involves arranging.
B. Determination of the combination.
Total number of people (n) = 185
Number of chosen people (r) = 2
Number of combination (ₙCᵣ) =?
ₙCᵣ = n! / (n – r)! r !
₁₈₅C₂ = 185! / (185 – 2)! 2!
₁₈₅C₂ = 185! / 183! 2!
₁₈₅C₂ = 185 × 184 × 183! / 183! 2!
₁₈₅C₂ = 185 × 184 / 2!
₁₈₅C₂ = 185 × 184 / 2 × 1
₁₈₅C₂ = 34040 / 2
₁₈₅C₂ = 17020
