SOLUTION: Question from GRE PowerPrep II Practice Test #2 Quant section 3 of 5 Question 13 or 20 A certain identification code is a list of five symbols: S1,S2,D1,D2,D3. Each of the firs

Algebra ->  Permutations -> SOLUTION: Question from GRE PowerPrep II Practice Test #2 Quant section 3 of 5 Question 13 or 20 A certain identification code is a list of five symbols: S1,S2,D1,D2,D3. Each of the firs      Log On


   



Question 645715: Question from GRE PowerPrep II Practice Test #2
Quant section 3 of 5
Question 13 or 20
A certain identification code is a list of five symbols: S1,S2,D1,D2,D3. Each of the first 2 symbols must be one of the 26 letters of the English alphabet, and each of the last 3 symbols must be one of the 10 digits. Repeated letters and digits are not allowed.) What is the total number of different identification codes?

Found 2 solutions by solver91311, somina:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


26 ways to pick the first symbol. For each of those 26 ways to pick the first symbol, there are only 25 ways to pick the second because of the no repetition rule, so 26 times 25 ways to pick the first two symbols. Then for each of those ways, 10 ways to pick the next digit, times 9 ways to pick the next digit, times 8 ways to pick the last one.

Altogether 26 X 25 X 10 X 9 X 8. You can do your own arithmetic.

John

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Answer by somina(1) About Me  (Show Source):
You can put this solution on YOUR website!
S1*D1 =26*10= 260
S2*D2 =26*10= 260
D3=10
260*260*10 = 676, 000