Question

The length, breadth and height of a room are 7 m. 5 m and 3 m respectively. Find the cost of painting the four walls and ceiling of the room at Rs 10 per sq m.​

Answer 1

$\huge\colorbox{yellow}{Given\:-}$

Length - 7 m

Breadth - 5 m

Height - 3 m

$\huge\colorbox{yellow}{To\:Find\:-}$

The cost of painting of four walls and ceiling of the room at ₹10 per sq m

$\huge\colorbox{yellow}{Solution\:-}$

Area of walls and ceiling = Lateral surface + Area of rectangle

$\small\underbrace\mathrm\red{Surface\:area\:of\:cuboid\:-}$

$2 \times (lb + bh + lh)$

Now

$= 2(bh + hl) + lb$

$= 2 \times (5 \times 3 + 3 \times 7) + 7 \times 5$

$= 2 \times (15 + 21) + 35$

$= 2 \times 36 + 35$

$= 72 + 35$

$= > 107$

Cost of painting = Area to be painted + Rate per sq m

$= 107 \times 10$

$\small\colorbox{pink}{=>\:1070}$

Hence, the cost of painting is ₹1070

$\huge\colorbox{yellow}{Thank\:You}$

$we \: value \: your \: care$