I don't remember exactly the explanation, but I recommend you try to learn more about number lines sometime when you aren't under stress from schoolwork, because they're pretty simple questions to answer once you get a better understanding of them!
The closest by default to 1100 cubic inches is taking two side and two front covers and that would give you 1080.12 cubic inches since two of the covers you must subtract 3 cm per side and side which would add 6 cm in total so outside would be 35 cm and indoor 29 cm
. According the graph
29*50*3= 4350 * 2 lid = 8700 cm3
30*50*3= 4500*2 lid = 9000 cm3
So 8700+9000 = 17700 cm3 to inches 3 = 1080.12 cm3