How many three-digit passwords are possible on a home security system keypad that consists of all the digits?
A. 10^3
B. 900
C. 26^3
D. 26*25*25
E. 10*9*8
The OA is A.
The question says it has to be a three-digit number, so should not the first digit just have 9 option than 10?
Likewise, I got 9*10*10 = 900 as the answer.
Can anyone please explain where did I go wrong? Thanks in advance.
How many three-digit passwords are possible on a home
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Three-digit passwords can begin with 0. So options like 011, 076, 002, and 000 are all valid passwords. This gives 10 options for each digit, or 10*10*10=10^3 possibilities in total.
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There are ten 1-digit numbers, including 0. Thus, the number of possible 3-digit passwords is 10 x 10 x 10 = 10^3.BTGmoderatorLU wrote:How many three-digit passwords are possible on a home security system keypad that consists of all the digits?
A. 10^3
B. 900
C. 26^3
D. 26*25*25
E. 10*9*8
Answer: A
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