Question

A metal sheet 27 cm long, 8 cm broad and 1 cm thick is melted into a cube. The difference between the surface area of the two solids, is

• A. $284\ cm ^ 2$
• B. $296\ cm ^ 2$
• C. $286\ cm ^ 2$
• D. $300\ cm ^ 2$

Answer 1

Answer: (C)

$286\ cm ^ 2$

Answer 2

Surface area of the metal sheet = 2(lb + bh + hl)
= 2(27 x 8 + 8 x 1 + 1 x 27)
= 2(216 + 8 + 27)
= 2(251) = 502 cm2
Edge of the cube which is formed after melting = l x b x h
i.e a3 = 27 x 8 x 1 (or) a = 6
Surface area of the cube = 6a2 = 216
Required difference = 502 - 216 = 286 cm2
Hence, option C is the correct answer.The correct option is (C): 286 cm ^ 2