For 5 and 9: I find that getting some graph paper out and treating each square as a character cell is useful. You can then draw what you want to see and count the number of spaces around things.
For example, a tree can be thought of as three triangles packed next to each other:
| / | \
|/B |C \
Triangle A is made by printing out spaces, while triangle(s) B+C is made of asterisks (or whatever it is your professor asked you to use).
Problem 10 is a variation of the "get the digits of an integer" problem. Remember that you can use the remainder operator (%) to get the least-significant digit and the integer division operator (/) to get rid of the least-significant digit.
123%10 --> 3
123/10 --> 12