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: 18,18+d,18+2d,18+3d,15
Last term: 18+4d=15 Use this to find d, then you can find and sum the three middle fractions.
