Answer:
A.10
B.10
C. 10,000
D. 8 hours
Step-by-step explanation:
Firstly, we should know that the numbers are labeled 0-9.
A. 10 digits
B. We already took one digit , but we still have 10 choices left again as numbers can be repeated.
C. For the first number, we have 10C1 choices since we are selecting 1 out of 10 numbers. This is the case for all the 3 renaming numbers. Hence the total number of possible passwords are
(10C1)^4 = 10,000 possible password combinations
D. That is (10,000*3)/60 in minutes = 500 minutes = 500/60 = 8.3333 , approximately 8hrs
