Insert three fractions between \(1/8\) and \(1/5 \) so the five fractions form an arithmetic sequence. What is the sum, expressed as a common fraction, of these three new fractions?

Like so:

Sequence: \(\frac{1}{8}, \frac{1}{8}+d, \frac{1}{8}+2d, \frac{1}{8}+3d, \frac{1}{5}\)

Last term: \(\frac{1}{8}+4d=\frac{1}{5}\) Use this to find d, then you can find and sum the three middle fractions.