Question

Three equal cubes are placed adjacently in a row. Find the ratio of the total surface area of the resulting cuboid to that of the sum of the total surface areas of the three cubes:

• A. 5 : 7
• B. 7 : 9
• C. 9 : 7
• D. None of these

Answer 1

The correct option is B 7 : 9

Let us consider that surface area of each face of the cube $1c{m}^3$.
$\therefore$ Total surface area of the cuboid = $14c{m}^2$
and Total surface area of the 3 cubes = $18c{m}^2$
Hence, required ratio =14 : 18 = 7 : 9