The dimensions of a room are 12.5 m by 9 m by 7 m. There are 2 doors and 4 windows in the room; each door measures 2.5 m by 1.2 m and each window 1.5 m by 1 m. Find the cost of painting the walls at Rs. 3.50 per square metre.
Given,
Dimensions of room = 12.5m ×9m × 7m
Dimensions of each door = 2.5m ×1.2m
Dimensions of each window = 1.5m ×1m
Area of four walls including doors and windows = 
= 
Area of 2 doors and 4 windows = 
Area of only walls = 301 – 12 = 289 m2
Hence,
Cost of painting walls at rate Rs.3.50 per square metre = Rs.(3.50 ×289) = Rs.1011.50
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