BreakEven/productivity/salary/employees If employees’ salaries are increased by 20%, what is the increase in productivity required to break even?

Can someone assist me in solving this question? 

Productivity =  (output per period)/(number of employees)

How is productivity related to the employees salaries?

Thank you
Break even is when your [economic] profits equals to zero:

\begin{align*}
\text{Cost} &amp;= \text{Revenue}\\
N \cdot w &amp;= Q \cdot P
\end{align*}

where $N$ is the number of workers, $w$ is wages, $Q$ is quantity produced, and $P$ is price.

An $x$% increase in productivity is the ability to hire the same amount of workers and get $x$% more output.

Assume that $N$ and $P$ remains unchanged, a 20% increase in wages would lead to the LHS's being $L \cdot 1.2w$ instead. How would the RHS need to change to maintain equality?