Answer:
2n+13
Step-by-step explanation:

For number 3 the problem solving it can be What is the difference between the T REX and the triceratops
The last one u could put Add up all the dinos and what will u get.
We have 26 letters and 10 digits.
So, we have 26 choices for the first letter, 25 choices for the second letter (we can't pick the one we already chose), and 10 choices per digit (we can always choose any digit, because we can repeat them).
This leads to a total of

possible car targs.