As a fraction, length of the 15 rods = 8 4/7 feet
As decimal, length = 8.57 feet
Explanation:initial length pipes = 4 feet
Dividing the length of the pipe into 7:
[tex]\begin{gathered} length\text{ }of\text{ each rod = }\frac{initial\text{ length}}{7\text{ parts}} \\ length\text{ }of\text{ each rod }=\frac{4}{7}\text{feet} \end{gathered}[/tex]length of 15 of those rods:
[tex]\begin{gathered} \text{length = 15 }\times\text{ length of each rod} \\ \text{length = 15 }\times\text{ }\frac{4}{7} \end{gathered}[/tex][tex]\begin{gathered} length\text{ of 15 rods = }\frac{60}{7} \\ Total\text{ length of 15 rods = 8}\frac{4}{7}\text{ or 8.57 f}eet \end{gathered}[/tex]