Question

How many possible three-digit passwords can be formed using digits 0 through 9 if digits are repeated?

30 ,
720 ,
1,000 ...?

Answer 1

The correct option is 3.

Explanation:

Total digits 0 to 9 are

0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Total number of digits is 10. It means total possible ways to select the first digit of the password is 10.

Since the reparation is allowed, therefore the possible ways to select the second and third digit of the password is 10.

Total possible ways to form a three-digit passwords is

`10* 10* 10=1000`

Therefore the correct option is 3.

Answer 2

I think the correct answer from the choices listed above is the second option. There would be about 720 possible three-digit passwords that can be formed using digits 0 through 9 if digits are repeated. THis can be calculated by getting 10P3 in a calculator. Hope this answers the question.