Q. What is the total number of different 13 -letter arrangements that can be formed using the letters in the word REVERBERATION?Answer:
Count and Identify Letters: Count the letters in REVERBERATION and identify any repeating letters.REVERBERATION has 13 letters with the following counts: R−3, E−3, V−1, B−1, A−2, T−1, I−1, O−1, N−1.
Calculate Total Arrangements: Calculate the factorial of the total number of letters to find the total arrangements without considering repetitions.Total arrangements = 13!=13×12×11×…×1.
Calculate Factorials for Repeating Letters: Calculate the factorial of the number of each repeating letter to account for indistinguishable arrangements.R has 3 repeats, E has 3 repeats, and A has 2 repeats.So, we have 3! for R, 3! for E, and 2! for A.
Divide Total Arrangements: Divide the total arrangements by the product of the factorials of the repeating letters to get the number of distinct arrangements.Distinct arrangements = (3!×3!×2!)13!.
Perform Calculations: Perform the calculations.13!=6,227,020,8003!=62!=2Distinct arrangements = (6×6×2)6,227,020,800=726,227,020,800=86,486,400.