Each of the length, breadth and height of a cuboid is decreased by 12 percent.…

2024

Each of the length, breadth and height of a cuboid is decreased by 12 percent. What is the percentage decrease in the total surface area of the cuboid?

  1. A.

    20.24 percent

  2. B.

    24.78 percent

  3. C.

    18.92 percent

  4. D.

    22.56 percent

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Show answer & explanation

Correct answer: D

To determine the percentage decrease in the total surface area of a cuboid when each dimension is decreased by 12%, we can use the following approach.

Step-by-Step Calculation
Original Surface Area:
The surface area (SA) of a cuboid is given by the formula:
SA_original = 2(lb + bh + hl)

New Dimensions:
If each dimension (length l, breadth b, and height h) is decreased by 12%, the new dimensions become 88% of their original values:
l_new = 0.88l
b_new = 0.88b
h_new = 0.88h

New Surface Area:
SA_new = 2((0.88l * 0.88b) + (0.88b * 0.88h) + (0.88h * 0.88l))
SA_new = 2(0.88)^2 * (lb + bh + hl)
SA_new = 0.7744 * SA_original

Percentage Decrease:
The new area is 77.44% of the original area. The percentage decrease is:
Decrease = 100% - 77.44% = 22.56%

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