Answer:
30,240 ways, if I am restricted to using A, B, and C for letters
Step-by-step explanation:
This uses Combinatorics from Discrete Math.
so.
3 letters and 4 digits.
26 letters from alphabet, but you want to choose first letters. no repeats...
Does this mean only letters A, B, and C ?
digits from 10 digits...
I imagine 7 empty slots , and the number of ways they occur together is by the product of the number of choices each box has.
3*2*1 * 10*9*8*7 = 6 * 5040 = 30,240 ways
This is an example of the commutative property of multiplication.
That property states:

So using that property, we can figure out that
3 should be in the blank.
Alright so lets start with an arbitrary amount of students. Just to help us visualize the problem.
Say, 100 students for the first year when it was founded?
So far,
1996 - 100 students
From 96' to 97', it doubles. So:
1996 - 100 students
1997 - 200 students
From 97' to 98', it doubles AGAIN.
1996 - 100 students
1997 - 200 students
1998 - 400 students
So, what the percentage increase from 100, to 400?
Well, 100 x 4 gives us 400, so it's a 400 percent increase.
2 is correct, because:
1) we have a close interval
2)we must have node on x=-5