Question

a door of breadth 1 m and height 2 m is fitted in a wall. The length of the wall is 4.5m and the height is 3.6 m. Find the cost of washing the wall, if the rate of white washing the wall is Rs 20 per m²

Answer 1

we need to find surface area over which we have to paint.
It means area of 4 walls excluding door.

Area of 4 walls = 2h(l+b)
= 2×2(4.5+4.5) u had not given breadth
=4×9
=36 m^2

Area of door = 1×2 = 2m^2

so area to be painted is 36-2= 34m^2

total cost = 34×20
= 680 rupees

Answer 2

Answer:

Answer:

$\huge\star{\underline {\underline{\pink{Q}{uestion}}}}\star\:$

A door of length 2 m. and breadth 1 m. is fitted in a wall. The length of the wall is 4.5 m. and the breadth is 3.6 m.

Find the cost of white washing the wall, if the rate of white washing the wall is 20 per m².

$\huge\star{\underline{\underline{\pink {A}{nswer}}}}\star\:$

White washing of the wall has to be white washed excluding the area of door.

$\red {=》} Area \:of \:the\: wall\: including\: door = length × breadth\\ \red {=》} 4.5 m. × 3.6 m. = 16.2 m²\\ \red {=》} Area of rectangular door = length × breadth\\ \red {=》} 2m. × 1m. = 2 m² \\\huge{\underline{\underline{Now,}}}$

Area of wall excluding door = Area of wall including door - Area of rectangular door

$\red {=》}16.2 m² - 2 m²\\ \red {=》} 14.2 m²\\ \huge {\underline {\underline {Given,}}}$

The rate of white washing of 1 m² the wall = 20

The rate of white washing 14.2 m² the wall = 20 × 14.2

$\red {===》} 284\\ \huge\green{\underline {\underline{\mathtt {Final\: Answer}}}}$

The cost of white washing

of the wall excluding door

is 284