Width of the room left uncovered = 0.25 m
Now,
Length of the room to be carpeted = 4.9 - (0.25 + 0.25) = 4.9 - 0.5 = 4.4 m
Breadth of the room be carpeted = 3.5 - (0.25 + 0.25) = 3.5 - 0.5 = 3m
Area to be carpeted = 4.4 x 3 = 13.2m2
Breadth of the carpet 80 cm = 0.8 m.
We know:
Area of the room = Area of the carpet
Length of the carpet = \(\frac{Area\,of\,the\,room}{Breadth\,of\,the\,carpet}\)
= \(\frac{13.5}{0.8}\)
= 16.5m
Cost of 1 m carpet = Rs 80
Cost of 16.5 m carpet = 80 x 16.5 = Rs 1,320