A room 4.9 m long and 3.5 m broad is covered with carpet, leaving an uncovered margin of 25 cm all around the room.

Width of the room left uncovered = 0.25 m
Now,

Length of the room to be carpeted $=4.9-(0.25+0.25)=4.9-0.5=4.4 \mathrm{~m}$

Breadth of the room be carpeted $=3.5-(0.25+0.25)=3.5-0.5=3 \mathrm{~m}$

Area to be carpeted $=4.4 \times 3=13.2 \mathrm{~m}^{2}$

Breadth of the carpet = 80 cm = 0.8 m
We know:
Area of the room = Area of the carpet

Length of the carpet $=\frac{\text { Area of the room }}{\text { Breadth of the carpet }}$

$=\frac{13.2}{0.8}$

$=16.5 \mathrm{~m}$

Cost of 1 m carpet = Rs 80

Cost of $16.5 \mathrm{~m}$ carpet $=80 \times 16.5=$ Rs 1,320