Please help me with my math​

SA = 480 cm²

Step-by-step explanation:

Surface area of the composite figure given in the picture = (Surface Area of the triangular prism on the top - area of the rectangular base) + (Surface area of the rectangular prism - Area of the rectangular base)

Surface area of the triangular prism = Area of the triangular bases + (perimeter of the base × Height)

= + [(5 + 5 + 8)×12]

= 24 + 216

= 240 cm²

Area of the rectangular surface of the prism = 8 × 12 = 96 cm²

Surface area of the rectangular prism = 2(lb + bh + hl)

Here, l = Length, b = width and h = Height of the rectangular prism

                                                  = 2(8 × 12 + 12 × 6 + 6 ×8)

                                                  = 432 cm²

Surface area of the composite figure = (240 - 96) + (432 - 96)

                                                                = 144 + 336

                                                                = 480 cm²

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5

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.