Answer:
Step-by-step explanation:
Please refer to the attachement. I defined the height (H), width (W), and length (L) and set:
H = 4m and W = (1/3)L. The total cost of 640 Rs/m^2 is divided by the rate cost of Rs 5/m^2 to give 128 m^2 that was plastered. The total area of the walls must be 128 m^2, so then calculate the total wall area: The walls for the length are 2*LH and for the width are 2*WH. Substituting, we have a total of 8*L + (4/3)L = 128 m^2. Solve for L to obtain L = 12m. W is 1/3L, or 4m. The room is (W,L,H) 4, 12, and 4 meters. The floor is W*L, or 48m^2. At Rs 250/m^2, the rug will cost Rs 12000. Ouch.