Question

2. For many computer tablets, the owner can set a 4-digit pass code to lock the device.

Answer 1

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