Ask Question
5 August, 11:39

The number of 3-digit telephone area codes that can be made if repetitions are not allowed is?

a. 100

b. 720

c. 1,000

d. 504

+5
Answers (1)
  1. 5 August, 12:09
    0
    Each of the 3 digits can be from 0 to 9, so each of the digits can have 10 values.

    10 * 10 * 10 = 1,000

    However, if repetition is NOT allowed, then the first digit can be ANY digit (10 possibilities). The second digit can be ANY digit except what the first digit is (9 possibilities). The third digit can be ANY digit except what the first digit is or what the second digit is (8 possibilities).

    Total area codes = 10 * 9 * 8 = 720

    Answer is b
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “The number of 3-digit telephone area codes that can be made if repetitions are not allowed is? a. 100 b. 720 c. 1,000 d. 504 ...” in 📗 Mathematics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers