Let us assume that the lotion has 50% alcohol and 50% water.ratio = 1:1As the total solution is 9mlalcohol = water = 4.5mlNow if we want the quantity of alcohol = 30%The quantity of water = 70%The new ratio = 3:7Let x ml of water be addedWe get, 4 . 5 4 . 5 + x = 3 7 => x=6Hence 6ml of water is added.