Proving properties of magic squares: magic constant, center, corners

[imprank6]

Homework Statement

a) Show that the magic constant of an nth order normal magic square is n(n^2+1)/2.
b) Show that the center of a 3x3 must be occupied by the number 5.
c) Show that in a normal magic square of 3x3 the number 1 can never occur in a corner cell.

Homework Equations

None needed

The Attempt at a Solution

I have no idea where to start.

 

[Tinyboss]

For part (a), consider the sum of the numbers in the entire square. How does that relate to the magic constant?

For (b), try putting 1 in the center and see if you can tell why it doesn't work. Generalize.

Part (c) has a similar reason. Go ahead and put the 1 in a corner and see if you can get the three rows touching it to add up.