331/3 of them on the floor, and another 331/3 of them on the ceiling.
There are undoubtedly many more on the walls, but we can't calculate those
without knowing the height of the room.
The answer depends on the units used for 15 and 8. It should be obvious to you that the square footage of a 15 ft x 8 ft area will be somewhat different form that of 15 yards x 8 yards!
150 square feet
32 square feet
165 square feet (15 x 11 = 165)
400 square feet.
525 square feet.
120 square feet.
252 square feet.
324 square feet.
130 square feet.
352 square feet.
140 square feet.
770 square feet.
240 square feet
300 square feet.
162 square feet.