Answer:
7 coats (cups) of paint
Explanation:
The dimensions of the room are;
The length of the room, l = 4 m
The width of the room, w = 3 m
The height of the room h = 2.5 m
The area one coat (taking the coat to mean cup) of paint can paint, A/c = 5 m²/cup
The total surface area of the room wall, A = 2 × l × h + 2 × w × h
∴ A = 2 × 4 m × 2.5 m + 2 × 3 m × 2.5 m = 35 m²
The amount of paint to be used, c = A/(A/c)
∴ c = 35 m²/(5 m²/cup) = 7 cups
The amount of paint to be used, c = 7 cups