The score for the first two essays are 95 and 83.
Let the score in third essay be x.
The average is 85.
Therefore,
[tex]\begin{gathered} \frac{95+83+x}{3}=85 \\ 178+x=255 \\ x=255-178 \\ x=77 \end{gathered}[/tex]So, the score in third essay will be 77.
