Question

the length, breadth& height of a room are 5m,4m3m respectively. find the cost of white washing walls of the room and ceiling at the rate of Rs7.5 per metre square​

Answer 1

Answer:

here is ur answer

l=5m

b=4m

h=3m

LSA +l*b=2*(l+b)*h+l*b

          =2*(5+4)*3+5*4

           =2*9*3+20

            =54+20

               =74

cost of white washing 1m=rs 7.5

cost of 74m=7.5*74=rs555

Answer 2

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

Step-by-step explanation:

Please mark as brainliest