Is it possible to calculate a voltage for microwave energy
generating in oven?
Is there any formula relating frequency and voltage and it
should be independent of speed?

Alok and Bhanu play the following min-max game. Given the
expression
N = 9 + X + Y - Z
Where X, Y and Z are variables representing single digits (0
to 9), Alok would like to maximize N while Bhanu would like
to minimize it. Towards this end, Alok chooses a single
digit number and Bhanu substitutes this for a variable of
her choice (X, Y or Z). Alok then chooses the next value and
Bhanu, the variable to substitute the value. Finally Alok
proposes the value for the remaining variable.
Assuming both play to their optimal strategies, the value of
N at the end of the game would be
27
0.0
20
18