Two cubes of each edge ‘a’ is joined end to end then the surface a

1.	Two cubes of each edge ‘a’ is joined end to end then the surface area of the resultant cuboid is ……………. A) 9a2 B) 10a2 C) 18a2 D) 16a2
Answer» Correct option is (B) \(10a^2\) Two cubes of each edge a is joined end to end then the length of formed cuboid = 2a, breadth of formed cuboid = a and height of formed cuboid = a. \(\therefore\) Surface area of resultant cuboid \(=2\,(2a\times a+a\times a+a\times 2a)\) \(=2\,(2a^2+a^2+2a^2)\) \(=2\times5a^2=10a^2\) Correct option is B) 10a²

Two cubes of each edge ‘a’ is joined end to end then the surface area of the resultant cuboid is ……………. A) 9a2 B) 10a2 C) 18a2 D) 16a2

Answer»

Correct option is (B) \(10a^2\)

Two cubes of each edge a is joined end to end then the length of formed cuboid = 2a,

breadth of formed cuboid = a and

height of formed cuboid = a.

\(\therefore\) Surface area of resultant cuboid \(=2\,(2a\times a+a\times a+a\times 2a)\)

\(=2\,(2a^2+a^2+2a^2)\)

\(=2\times5a^2=10a^2\)

Correct option is B) 10a²