Madison can spit a seed 20% farther than Billy's 30 inches so that's .20*30 = <<20*.01*30=6>>6 inches farther
Billy spits a seed 30 inches and Madison can spit 6 inches farther for a total of 30+6 = <<30+6=36>>36 inches
Ryan can spit a seed 50% shorter than Madison's 36 inches for a total of .50*36 = <<50*.01*36=18>>18 inches
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