Combinations = n! / (n - r)! r!

In this case:
n = 4
r = 3
Combinations = 4! /(4-3)! 3! = 24/(1)(6) = 24/6 = 4
Answer:
4 arrangements
Answer: Great Question. In order to anwer your question where is the zip line
Step-by-step explanation:
Answer:
AD = 84
Step-by-step explanation:
Since B is the midpoint of AC then AB = BC = 2x - 5
Since C is the midpoint of AD then AC = CD, thus
AB + BC = CD, that is
2x - 5 + 2x - 5 = x + 29
4x - 10 = x + 29 ( subtract x from both sides )
3x - 10 = 29 ( add 10 to both sides )
3x = 39 ( divide both sides by 3 )
x = 13
Hence
AD = AB + BC + CD
= 2x - 5 + 2x - 5 + x + 29 = 5x + 19, thus
AD = (5 × 13) + 19 = 65 + 19 = 84