title = "Table of Contents"

bookinfo = ["Numbers", 1, "Letters", 72, "Variables", 118]
width = 50
puts bookinfo.join(", ")
puts title.center(width)

3.times do |ch|
  puts(("Chapter #{(ch + 1).to_s}: " + bookinfo[2*ch].to_s).ljust(width/2) + ("page " + bookinfo[(2*ch)+1].to_s).rjust(width/2))
end