\[2,65 \cdot (n - 3,06) = 4,24\]
\[n - 3,06 = 4,24\ :2,65\]
\[n - 3,06 = 1,6\]
\[n = 1,6 + 3,6\]
\[n = 4,66.\]
\[Ответ:\ n = 4,66.\]