Solve the problem.
-A signal is made by placing 3 flags, one above the other, on a flag pole. If there are 7 different flags available, how many possible signals can be flown?
A) 21
B) 35
C) 343
D) 210

Question

Quizplus · Accepted Answer

Since there are 7 different flags available and 3 positions to place them in a specific order (one above the other), we use permutations because the order matters. The formula for permutations is P(n, r) = n! / (n-r)!, where n is the total number of items to choose from, r is the number of items to choose, "!" denotes factorial, which means the product of all positive integers up to that number (e.g., 5! = 5×4×3×2×1 = 120). Here, n=7 (flags) and r=3 (positions). So, P(7, 3) = 7! / (7-3)! = 7! / 4! = (7×6×5×4!) / 4! = 7×6×5 = 210.

Solve the Problem. -A Signal Is Made by Placing 3 Flags, One Above