The length, width and height ratio of a

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Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 3D

Question:

The length, width and height ratio of a cuboid is 7 : 5 : 4 and its entire surface area is 2656 square cm. Find its width.

Options:

22 cm

20 cm

18 cm

25 cm

Correct Answer:

20 cm

Explanation:

l : b : h = 7x : 5x : 4x

ATQ,

T.S.A. = 2 [ lb + bh + hl ]

2656 = 2[ 35x²+ 20x²+ 28x²]

2656 = 2 [ 83x²]

83 x²= 1328

x²= 16

x = 4

Now,

b = 5x = 5 × 4 = 20 cm