Question

Two cubes each of volume 27 cm^3 are joined together. Find the surface area of the resulting solid?

(a) 109.4 cm^2

(b) 126 cm^2

(c) 150 cm^2

(d) 189.4 cm^2

I have been asked this question in examination.

The question is from Surface Area and Volume of Combination of Solids in division Surface Area and Volumes of Mathematics – Class 10

Answer 1

Correct choice is (b) 126 cm^2

The explanation: Volume of cube = a^3 = 27

a = 3 cm

Joining 2 cubes results in a cuboid. Length of the cuboid (l) = 3 + 3 = 9 cm

Height of the cuboid (h) = 3 cm

Breadth of the cuboid (b) = 3 cm

Surface area of cuboid = 2(lb + bh + hl) = 2(27 + 9 + 27) = 126 cm^2