Question

6. A password contains at least 8 distinct digits. It takes 12 seconds to try one combination, what is the minimum amount of time required to guarantee access to the database?

Answer 1

Answer:

6048 hours is required to guarantee access to the database

Explanation:

If a password contains 8 distinct digits, then there are P(10,8) permutations possible

P(10,8)=10! / (10-8)! = 10!/2! = 1814400

Since it takes 12 seconds to try one combination,

1814400×12 = 21772800 seconds is required to guarantee access to the database. This is $\frac{21772800}{3600}=6048 hours$