grid-calculator.rb

def calculate_grid(width, cols)
    results = []
    (0..width).each do |n|
        gutter = n.to_f
        col = (width - (gutter * (cols + 1))) / cols
        break if col < 0
        results << "col: #{col.to_i}px / gutter: #{gutter.to_i}px" if col % 1 == 0
    end
    results
end

puts calculate_grid ARGV[0].to_i, ARGV[1].to_i