What is the area of the area of this figure? use 3.14 for pi its a rectangle and half a circle connected, on top of the rectangle it says "7 cm" and the dotted line of the half circle say "3 cm"

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