How many different three-letter code words
can you make using the letters A,B and C
(a) If repetition of the letters is NOT Permitted
(b) If repetition of the letters IS Permitted.
2007-11-21 15:22:37 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
a) 3! (3 * 2 * 1) = 6
b) 3^3 = 27
2007-11-21 15:35:05 · answer #1 · answered by Jay 4 · 1⤊ 0⤋
A)3x2x1=6
B)3x3x3=27
2007-11-21 15:35:34 · answer #2 · answered by seacod 2 · 0⤊ 0⤋
CASE A (Repetition *is not* permitted)
3 choices for the first letter
2 choices for the second letter
1 choice for the last letter
3 x 2 x 1 = 6 ways
ABC, ACB, BAC, BCA, CAB, CBA
CASE B (Repetition *is* permitted)
3 choices for the first letter
3 choices for the second letter
3 choices for the last letter
3 x 3 x 3 = 27 ways
AAA, AAB, AAC, ABA, ABB, ABC, ACA, ACB, ACC,
BAA, BAB, BAC, BBA, BBB, BBC, BCA, BCB, BCC,
CAA, CAB, CAC, CBA, CBB, CBC, CCA, CCB, CCC
2007-11-21 17:34:16 · answer #3 · answered by Puzzling 7 · 0⤊ 0⤋