Question

the length breadth and height of a room are 5 m , 4 m and 3 m respectively . find the cost of white washing the inner of the room and ceiling at the rate of rupees 50 per square meter. ​

Answer 1

Answer:

3,7 00

Step-by-step explanation:

Given,

L=5m

b=4m

h=3m

T.S.A=2×(L.b+ b.h+h.l)

=2×(5×4+4×3+3×5)

=2×(20×12×15)

=2×47

=94m²

Again,area of the floor =l×b

=5×4

=20m²

Area of the four walls and the ceiling

=T.S.A-Area of the floor

=94-20

=74m²

cost of 1m²=Rs 50

cost of 74m²=Rs 50×74

=Rs 3,700

Answer 2

$\mathfrak{\huge{\underline{Answer:}}}$

$\textbf{\underline{\underline{Length = }}}$ 5m

$\textbf{\underline{\underline{Breadth= }}}$ 4m

$\textbf{\underline{\underline{Height= }}}$ 3m

$\textbf{\underline{\underline{Total\:Surface\:Area :}}}$

2(lb + bh + lh) cm^2

[ l = length, b = breadth, h = height ]

2(5 × 4 + 4 × 3 + 5 × 3)

2(20 + 12 + 15)

2 × 47

94 cm^2

$\textbf{\underline{\underline{Area of floor : }}}$

Length × Breadth

5 cm × 4 cm

20 cm^2

$\textbf{\underline{\underline{Inner\:Room = }}}$

Total Area - Area of floor

(94 - 20) cm^2

74 cm^2

$\textbf{\underline{\underline{Cost\:Of\:White\:Washing :}}}$

@50 per square meter

Cost of 74 m^2 :

74 × 50

Rs 3700