Question

8. A door of length 2 m and breadth 1m is fitted in a wall. The length of the
wall is 4.5 m and the breadth is 3.6 m (Fig11.6). Find the cost of white
washing the wall, if the rate of white washing the wall is 20 per m².​

Answer 1

Given:-

$\bf\large{\red{Length \: of \: door=2m}}$

$\bf\large{\red{Breadth \: of \: door=1m}}$

$\bf\large{\red{Area=Length×Breadth}}$

$\bf\large{\red{Area=(1×2)m=2m²}}$

$\bf\large{\blue{Length \: if \: wall=4.5m}}$

$\bf\large{\blue{Breadth \: of \: wall=3.6m}}$

$\bf\large{\blue{Area=(4.5×3.6)m=16.2m²}}$

Area of wall to be white washed=Area of wall-Area of door

=>16.2m²-2m²=14.2m²

Rupees needed to white wash 1m²=₹20

Rupees needed to white wash the wall =20×14.2=₹284

$\color{pink}{\bf{Hope \: it \: helps \: you...}}$

Answer 2

Step-by-step explanation:

area to be white washed

=area of wall -Area of door flame

WALL

length = l =4.5 m

breadth=b=3.6 m

area of wall = length ×breadth (l ×b)

=4.5×3.6

=45/10 ×36/10 sq. m.

=9/2×36/10

=9/1×18/10

= 162/10

=16.2m²

door frame

length = l = 2 m

breath =b= 1 m

area of door frame =length ×breadth (l×b)

= 2×1

2 m²

thus,

area to be washed =16.2-2

14.2m²

now

cost of white washing 1m² of wall = rs 20

cost of white washing 14.2 m²of wall = Rs 20×14.2

=20×142/10

=Rs 2× 142

= Rs 284

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