The volume of a wall whose height is 10 times its width and whose length is 8 times its height is 51.2 m3. What is the cost (in Rs.) of painting the wall on one side at the rate of Rs. 100/m2?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 12800.
Let the width be x.
height of the wall = 10x
Length of the wall = 8 × 10x = 80x.
Volume = 51.2 m3
80x × 10x × x = 51.2
x3 = 0.064
x = 0.4
Surface area of one side of the wall = 80x × 10x = 800 × 0.4 × 0.4 = 128
Cost = 128 × 100 = 12800.