The cost of painting the surface of a solid cuboid of dimensions 40 cm × 36 cm × xcm at ₹20 per 100 cm² is ₹ 1,032. What is the value of x?

Correct option is C

Surface Area = 2(lb + bh + hl)
Where:

l = length = 40 cm
b = breadth = 36 cm
h = height = x cm
So, the surface area of the cuboid is:

Surface Area = 2(40 * 36 + 36 * x + 40 * x)
Now, we know the cost of painting 100 cm² is ₹20. So, the cost of painting the entire surface area is:

Cost = (Surface Area / 100) * 20
We are given that the cost is ₹1,032. So, we can set up the equation:

(2(40 * 36 + 36 * x + 40 * x) / 100) * 20 = 1032
Now, let's solve for x:

2(1440 + 76x) = 5160
2880 + 152x = 5160
152x = 2280
x = 15
Therefore, the value of x is 15 cm.