A, B, C are three numbers. Let
@ (A, B) = average of A and B,
/ (A, B) = product of A and B, and
X (A, B) = the result of dividing A by
The sum of A and B is given by
/(@( A, B), 2)
X(@(A, B), 2)
@(/(A, B), 2)
@(X(A, B), 2)