The volume of a cuboid is 54cm3. If the length, width and height of the cuboid are in the ratio 2:1:1 respectively, find its total surface area

108cm²

90cm²

80cm²

72cm²

Correct answer is B

V = L x B x H

V = \(2x \times x \times x = 2x^3\)

= 54cm3

i.e. 2x3 = 54

x3 = \(\frac{54}{2}\) = 27

x = 3\(\sqrt{27}\)

x = 3

L = 2x i.e. 2 x 3 = 6cm

B = x i.e. x = 3cm

H = x i.e. x = 3cm

but A = 2(LB + LH + BH) = 2(6 x 3) + (6 x 3) + (3 x 3) = 2(18 + 18 + 9) = 2(45)

= 90cm2

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The volume of a cuboid is 54cm3. If the length, width and height of the cuboid are in the ratio 2:1:1 respectively, find its total surface area

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