What is the cost of painting of wall?
Answer: (3) Rs. 20160
The length and width of a rectangular wall = 30 meters and 24 meters
Then, area of rectangular wall = 30 x 24
= 720 m^2
The rate of painting is Rs.28 per square metre.
Therefore, cost of painting of wall = 720 x 28
= Rs. 20160
Hence, the correct answer is option (3) Rs. 20160.