Question

find the cost of whitewashing the walls of a room is 10 metre long and 6 metre wide and 4 metre high allowing 25 square metre for window etc. at rupees 50 per square metre ​

Answer 1

AnswEr :

• Length = 10 metre
• Breadth = 6 metre
• Height = 4 metre

$\underline{\bigstar\:\textsf{According to the Question Now :}}$

$:\implies\texttt{Required Area = CSA of Room - Windows}\\\\\\:\implies\tt Required\:Area = [2(Length+Breadth) \times Height] - Windows\\\\\\:\implies\tt Required\:Area = [2(10 \:m + 6 \:m) \times 4 \:m] - 25 m^2\\\\\\:\implies\tt Required\:Area =[2 \times 16 \:m \times 4 \:m] - 25 m^2\\\\\\:\implies\tt Required\:Area = 128 \: m^2 - 25 \: m^2\\\\\\:\implies\tt Required\:Area = 103 \:m^2\\\\\qquad\scriptsize{\bf{\dag}\:\textsf{Cost of White Washing}}\\\\:\implies\tt Cost = Required\:Area \times Rate\\\\\\:\implies\tt Cost = 103 m^2 \times Rs. \:50 \:per \:m^2\\\\\\:\implies\boxed{\blue{\tt Cost = Rs. \:5150}}$

⠀

$\therefore\:\underline{\textsf{Cost of white whasing of walls is \textbf{Rs. 5150}}}$

Answer 2

Answer:

$\large\boxed{\sf{Rs. \:5150}}$

Step-by-step explanation:

Dimensions of the given wall :-

Length, l = 10 m

Breadth, b = 6 m

Height, h = 4 m

For white washing, we need only the curved surface area of the walls.

.°. c.s.a = 2(l+b)h

=> c.s.a = 2(10+6) × 4

=> c.s.a = 8 × 16

=> c.s.a = 128 m sq.

Area of the windows = 25 m sq.

.°. Required area = 128 - 25 = 103 m sq.

.°. Cost of white washing = ₹(103×50)

Hence, Cost = ₹ 5150