Question 8
A door of length 2 m and breadth 1 m is fitted in a wall. The length of the wall is 4.5 m and the breadth is 3.6 m. Find the cost of whitewashing the wall, if the rate of whitewashing the wall is Rs. 20 per m2.
Area of rectangular door = length×breadth =2 m×1m = 2 m2
Area of wall including door = length×breadth = 4.5 m×3.6 m = 16.2 m2
Now, Area of wall excluding door
= Area of the wall including door - Area of door
= 16.2−2 = 14.2 m2
Since, the cost of whitewashing 1 m2 of wall = Rs. 20
Therefore, the cost of whitewashing 14.2 m2 wall = 20 × 14.2 = Rs. 284
Thus, the cost of whitewashing the wall excluding the door is Rs. 284