MATHEMATICS · Subjective · CBSE · Mathematics · Surface Areas and Volumes · Surface Areas and Volumes
Problem
The inside of a rectangular room is 12m long, 9m wide, and 4m high. All four walls and the ceiling are to be white-washed. The rate for painting the walls is ₹14 per square metre, while the ceiling is charged at ₹12 per square metre. Doors and windows occupying 15m2 of wall area will not be painted. An additional 8% of paint is required to allow for absorption and minor wastage.
(i) Calculate the net area of the four walls to be painted after deducting the area of doors and windows.
(ii) Find the area of the ceiling.
(iii) Determine the total area of painting work, including the 8% extra.
(iv) Compute the total cost of painting the room.