Answer: A. 
Step-by-step explanation:
Total digits on keypad = 5
According to permutation,
If repetition of digits is not allowed then the number of 5-digits passwords can be formed = 5!
= 5 x 4 x 3 x 2 x 1 [n!=n x (n-1) x (n-2)x ... x 1]
=120
The probability that someone guesses the correct code = 

Hence, the correct option is A.
Answer: 
Step-by-step explanation:
Given: The side of the square shaped traffic sign = 4x+3
We know that the area of square is given by:-

Therefore, the area of the side of the square shaped field is given by:-

We know that , 
Therefore,

Hence, 
Answer: It's 3.8
Step-by-step explanation:
Answer:
B. The width of the confidence interval would be smaller.
Step-by-step explanation:
By reducing the confidence level from 99% to 95%, the student assumes that there is more uncertainty about the new confidence interval than the previous one. That, being said, since the results aren't as certain, the confidence interval is widened towards a central average point because the new interval isn't as accurate.
Therefore, the answer is B. The width of the confidence interval would be smaller.