Question 281754
Assuming that there are no windows in the room then paint has to be done on 4 walls and ceiling and floor.

surface area of 4 walls will be = 4*10*8 = 320 square feet
surface area of roof and ceiling will be = 2*10*10 = 200 square feet

Total surface area to be painted = 320 + 200 = 520 sqaure feet