Assume that the three lengths are 15/16, 7/8 and 7/16 miles.
The total length of the fences is
[tex] \frac{15}{16}+ \frac{7}{8} + \frac{7}{16}\\\\= \frac{15+(7*2)+7}{16} \\\\= \frac{36}{16} \\\\= \frac{9}{4} \\\\=2\, \frac{1}{4} [/tex]
Answer: [tex]2\, \frac{1}{4}\,miles [/tex]
