Question

lor)
b) The length, breadth and height of a room are 5 m, 4 m and 3m
respectively. Find the cost of white washing the walls of the
room and ceiling at the rate of Rs. 8.50 per m2.
[Turn Over​

Answer 1

$\huge \boxed{ \green{ \mathfrak{solution}}}$

Given:

•Length= 5m

•Breadth= 4m

•Height=3m

First find area of wall

✧area of wall = 2h(l+b)

=2×3(9)

=54m^2

Now find Area of ceiling :

✧ Area of ceiling = l×b

= 5×4

=20 m^2

✧ Total area = Area of wall + Area of ceiling

= 54+20

= 74 m^2

Now ,

✧cost = Total area × 8.50

= 74×8.50

= 629

Hence the cost of white washing the walls of the rooms and ceiling is

$\huge \: \boxed{ \red{\mathfrak{ rs \: 629}}}$

Answer 2

${ \bold {\large{\red {\underline {\underline{ \star \: {given}}}}}}}$

$\star \: length = 5m.$

$\star \: breadth = 4m.$

$\star \: height = 3m.$

${ \bold \red {\large {\underline {\underline{ \star \: {answer}}}}}}$

$area \: of \: wall \: of \: room \: = 2(l + b) \times h$

putting the given value________

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 2(5 + 4) \times 3. \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 20 {m}^{2} .$

Now ,

$area \: of \: celling = l \times b. \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 5 \times 4. \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 20 {m}^{2} .$

The Total area = Area of wall of room + Area of celling.

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \rightarrow \: 54 + 20. \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \rightarrow 74.$

A/Q,

The rate of cost = Total area * Given cost.

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \rightarrow \: 74 \times 8.50. \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \rightarrow \: 629.$

${\huge{\red {\star \: \mathfrak{rs \rightarrow 629.}}}}$