If there are 4 quarts in a gallon, and 2 pints in a quart, and 2 quarts in a pint, then how many cups are in a gallon? show your calculation or explain how you arrive at the answer

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters