Answer:
a) 
b) 0.27778
Step-by-step explanation:
a)
There are 26 lowercase letters and 10 digits.
The character that must be a digit can be generated in 10 different ways and the others, in 26+10=36 different ways.
Since the password is 6 characters long, by the Fundamental Rule of Counting there are
10*36*36*36*36*36 = 604,661,760
In scientific notation this number can be expressed as
b)
By the <em>Fundamental Rule of Counting</em>, there would be
different combinations of 6 characters, but only the number computed in a) are valid combinations, so the probability of generating a valid password is

Let's look at an example.
We'll add the fractions 1/6 and 1/8
Before we can add, the denominators must be the same.
To get the denominators to be the same, we can...
- multiply top and bottom of 1/6 by 8 to get 8/48
- multiply top and bottom of 1/8 by 6 to get 6/48
At this point, both fractions involve the denominator 48. We can add the fractions like so
8/48 + 6/48 = (8+6)/48 = 14/48
Add the numerators while keeping the denominator the same the entire time.
The last step is to reduce if possible. In this case, we can reduce. This is because 14 and 48 have the factor 2 in common. Divide each part by 2.
The fraction 14/48 reduces to 7/24
Overall, 1/6 + 1/8 = 7/24
X=8 would you like me to explain why?