Question

The length, breadth and height of a room are 8.5 m, 7 m and 6.5 m respectively. Find the area of the four walls of the room. Hence, find the cost of whitewashing the walls of the room and its ceiling at the rate of 8 per square metre.​

Answer 1

L=8.5m
B=7m
H=6.5m
CSA of rectangle =2h(L+b)
=2*6.5(8.5+7)
=>2*6.5*15.5 = 201.5m^2
Area of ceiling =l*b=>8.5*7
=59.5m^2
Total area of four walls of the room and the ceiling =201.5+59.5=261m^2
Cost of whitewashing 1m^2=8 rupees
Cost of whitewashing 261m^2= 261*8=₹208