a classroom is 7m long 6m broad and 4m high the doors and windows occupy an area of 7m square find the cost of whitewashing the walls and roof at the rate Rs15 per m square
Answers
Answer:
rs. 2085
Step-by-step explanation:
area of the four walls = 2(length x height)+2(breadth x height)
=2(28)+2(24) sq. m=104 sq. m
area of the ceiling = length x breadth
= 42 sq. m
total area of four walls and ceiling = (104 + 42) sq. m = 146 sq. m
area to be whitewashed = (146 - 7) sq. m = 139 sq. m
total cost of whitewashing = area to be whitewashed x rate of whitewashing
= 139 x rs. 15=rs. 2085
Answer:
A
Step-by-step explanation:
Area of four walls = 2 ( l + b ) h
= 2 ( 7 + 6 ) 4
= 104 m ^2
Area of four walls without doors and windows = Area of four walls - Area of doors and windows
= 104 - 7 = 97 m ^2
Cost of white washing 1 m^2 Area of walls = Rs 15
Total cost of whitewashing = 97 × 15 = Rs 1455