Please answer all the questiion.
15. A man bought a rectangular plot of land for constructing a house. The plot is 30 m deep and 15 m in the front. According to the laws of the town, he has to leave vacant 3 m in the front, 3 m in the back and 2 m on each of other sides. What is the largest area on which he can construct his house?
16. The dimensions of the screen of a flat TV are 90 cm x 60 cm. The screen has a 4-cm-broad boundary all around. Find the area of the boundary.
17. The cost of a Carpet for the floor of a 8-m-long room is Rs. 16,000. Had the breadth been 1 m less, the cost would have been Rs.12,000. Find the breadth of the floor. Also find the cost per m^2 for carpeting the floor.
18. The length of a room is 3 m more than its breadth. If the area of the floor of the room is 70 m^2 then find the perimeter of the floor.
19. The cost of constructing a road is Rs 5,000 per 100 m^2. Find the cost of constructing a road 5 m broad surrounding a garden 100 m long and 10 m broad.
20. A rectangular wall of area 30 m^2 has a length of 10 m. It is to be painted blue from the base to a height of 2.5 m, leaving 1 m on each side. The rest is to be painted white. If the cost of white and blue paints required to paint per square metre are Rs.460 and Rs.475 respectively, and the labour cost per square metre is Rs. 25 for both the colours then find the total cost of painting the wall.