Projectiles A2 Mechanics (please help)

Note: I'm going to be a bit harsh, because no one at 8am or anytime of day really want to decipher steps and formulas and stuff without explanations.

I think the idea is there. Numerically the answer looked about right.
However do note that you were told to use g=10, not 9.81.

You probably want to write down some words to describe what you're trying to do.
For instance, I think you are trying to do two things in (a). Well, what are those two things?
Note the lack of equal signs. A number 313.6 floating around in the middle of your work means nothing.

Also, pay attention to signs.
For instance, you are saying acceleration (due to gravity) is positive. Why positive?
Not wrong per say in this instance, but when the system gets complicated, you might get confused.