To increase an amount by 30%, what single multiplier would you use? and To decrease an amount by 30%, what single multiplier would you use?

Several paint mixtures are made by mixing blue paint and white paint. paint colors blue paint white paint mixture a 5 cups 12 cups mixture b 6 cups 6 cups mixture c 4 cups 12 cups mixture d 5 cups 6 cups which mixture has the highest ratio of blue paint to white paint