Question

3. The length, breadth and height of a room is 5m, 4m and 3m. The cost of white washing its four walls at the rate of Rs. 7.50 per m2is

Answer 1

length = 5 m 

breadth = 4 m 

height = 3 m 

area of wall = 2h (L+  b)

                     = 2 * 3 (4 +5 )

                     = 6*9

                     = 54 sq m

area of cieling = l*b

                         = 5 * 4 

                        = 20 sq m

total area= area of cieling + area of cieling 

               = 54 + 20 sq m

               = 74 sq m

cost of white washinf for 1 sq m = rs 7.50

             so for 74 sq m = 7.50 * 74 sq m

                                        = rs 555

Answer 2

Step-by-step explanation:

L=5

b=4

h=3

area of 4 walls = 2(l+b) h

=2(5+4)3

=2×9×3

=54m2

cost of 1m2 of 4 walls= 7.50

cost of 54 m2= 54×7.50

=405