Answer:
10.
First, we need to find the volume of the open courtyard;
30 is the width and 18 is the length, 28 is the height.
30 x 18 x 28
= 15,120
Now we subtract that from the total volume of the whole building including the courtyard;
28 is the height, 64 the width, and 60 the length;
28 x 64 x 60
= 107,520
Now we subtract:-
107,520 - 15,120 = 92,400 cubic meters