Can someone explain these questions to me, especially the last one please.

Answer:
Step-by-step explanation:
A is 0.5 x 10 because the thickness of the sheets is 0.5 and there are ten sheets stacked together that thickness so how thick is the pile.
for B it is the answer of A plus one more sheet which is ( answer for A) + 0.5
for c just add another sheet on all sides wich is + 0.5 for each side and when you get that add that number to answer B and that it.