A classroom is 10 meters long, 8 meters wide and 4 meters high. It is necessary to paint the surrounding and roof walls of the classroom. The area of the classroom is 41.6 square meters except the doors, windows and blackboards. On average, 0.32 kg of lime is used per square meter. How many kg of lime is needed?

A classroom is 10 meters long, 8 meters wide and 4 meters high. It is necessary to paint the surrounding and roof walls of the classroom. The area of the classroom is 41.6 square meters except the doors, windows and blackboards. On average, 0.32 kg of lime is used per square meter. How many kg of lime is needed?

Total area: 10x8 + 10x4x2 + 8x4x2 = 224 square meters
Painting area: 224-41.6 = 182.4 square meters
Total Limestone: 182.4x0.32 = 58.368kg
Is that OK?