the expression is,
[tex]\frac{6}{78}<\frac{1}{n}<\frac{5}{55}[/tex][tex]\begin{gathered} \frac{6}{78}<\frac{1}{n} \\ n<\frac{78}{6} \\ n<13 \end{gathered}[/tex]Now,
[tex]\begin{gathered} \frac{1}{n}<\frac{5}{55} \\ \frac{1}{n}<\frac{1}{11} \\ n>11 \end{gathered}[/tex]so the number n is between 11 and 13
that is n = 12
thus, the answer is n = 12
