I like the 'question mark' at the end:
26 letters (English), 10 digits (0,1,...9)
26*26*10*10*10 = 676000
Now, this was for LLDDD (Letter Letter Digit Digit Digit)
It seems this is the order they want. Other wise, one should multiply by all the combinations in the order: LDLDD, DLLDD, etc ... (10 combinations), but again it seems they want this LLDDD
So 676000
Answer: 2.4 years or 28.8 months
The slope of a graph is rise over run. So count how many units up you move and put that over how many units right you move. If you are moving down or to the left it would be negative.
Answer:

2.835
3.330
Step-by-step explanation:

Let the linear approximation be L(x) at a = 0. This is given by

is the derivative of
. To find this, we use the form
If
, then 
By doing this and applying chain rule for the power (which is a function of x), we have

Then

Also 
Hence 
For
,
and 
Using this in
,

For
,
and 
Using this in
,

Answer:
0.3
Step-by-step explanation:
just subtract