question: Katerina makes designer jewelry.  Her specialty is topaz necklaces.  She uses 8 topaz gemstones per necklace, and fills the space between gemstones using sterling silver beads.  If each topaz gemstone is one inch long, each sterling silver bead is one-quarter of an inch long, and each necklace is made to a total length of 25 inches, how many sterling silver beads does Katerina use per necklace?
answer: 8 topaz gemstones, at 1 inch per gemstone, contribute a total of 8*1=<<8*1=8>>8 inches to each necklace.
  Since each necklace is 25 inches in length, then there are 25-8=<<25-8=17>>17 inches of space between gemstones.
  Since Katerina uses one-quarter inch sterling silver beads to fill space between gemstones, then she will require 17*4=<<17*4=68>>68 sterling silver beads per necklace.
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