The correct option is
A 15 mLet the breadth of the room be x m.
Therefore, length of the room be 3x2m.
Given, cost of carpeting the room at Rs 3.25 per m2 is Rs.175.50.
Total carpet area of the room =Rs175.5Rs3.25=54m2
⇒lb=54⇒3x2×x=54⇒x2=36⇒x=6m
So, breadth of the room =6m and length of the room =9m
Given, cost of papering the walls at Rs. 1.40 per m2 is Rs. 240.80.
Total area paper on the walls =Rs240.801.40=172m2
Given one door and two windows also occupy 8m2 area.
Therefore, area of four walls =172+8=180m2
⇒2(l+b)h=180
⇒2(9+6)h=180
⇒h=6m
Hence, the dimensions of the room are 9m×6m×6m.