QUESTION: Josephine put a frame round his picture which measured 36 cm by 34 cm. A margin 4cm wide was left all the way round. What was the area of the margin ? (NOTE:SORRY BUT UNFORTUNATELY THERE ISN`T A DIAGRAM)

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