trong một hộp đựng 20 viên bi màu đen khác nhau và 19 viên bi mài trắng khác nhau. hỏi có bao nhiêu cách sắp xếp cá viên bi thành hàng ngang mà có màu xen kẽ nhau?

answer:

total cost for tiles and paints is $924.  

step-by-step explanation:

we have been given that a community hall is in the shape of a cuboid. the hall is 40m long 15m high and 3m wide.

the paint will be required for 4 walls and ceiling.

let us find area of walls and ceiling.

therefore, the area of walls and ceiling is 1410 square meters.

given: cost for 10 litre of paint is $10 and 10 litre paint covers 25 square meter. therefore,

therefore, the total painting cost is $564.

tiles will be required for floor. let us find the area of floor.

given: 1m squared floor tiles costs $3. so,

therefore, the total tiles cost is $360.

now let us find combined total cost of tiles and paint.

therefore, the combined total cost of tiles and paint is $924.

the angles measure to 70 degrees, 70 degrees, 20 degrees, and 20 degrees