Question

the length breadth and height of a room are 5m 4m and 3m respectively find the cost of white wasing the inner of the room and ceiling at rate of $50 pe square metre

Answer 1

TSA = 2(l×b+b×h+h×l)
= 2(20+12+15)
= 2×47 =94m2
total cost = 50× 94 =4700

Answer 2

area of four walls of room =2h (l+b)
area. = 2×3(5+4)= 6×9=54m
area of ceiliing = l×b = 5×4=20m
total area = 20m+ 54m
= 74m
cost of white washing = 74×$50 = $3700