Question

The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of whitewashing the walls of the room and the ceiling at the rate of Rs.7.50 per sq.m.​

Answer 1

Answer:

Length, breadth and height of a room are 5 m, 4 m and 3 m.

Area of four walls of the room =2h(l+b)

=2×3(5+4)

=6(9)

=54 sq m

Area of the ceiling =l×b

=5×4

=20 sq cm.

Total area of the four walls and the ceiling of the room

=54+20

=74 sq cm

Cost of white washing = Rs 7.50 per sq m

Total cost of white washing =74×7.50= Rs 555

Answer 2

Answer:690 rupees

Step-by-step explanation:

$lateral \: surface \:area \: = 2height(length + breadth)$

= 2 x 3(5+4)

6(9)

72cm²

Lateral surface area = 72cm

a/q

Total area to be whitewash = L.S.A + area of ceiling

Area of ceiling = length x Breadth

5 x 4

20m²

Total area = 72+20

= 92cm²

Cost of whitewash = 7 .50 x 92

= 690 rupees