Two cubes each with side b are joined to form a cuboids. What is the surface area of this cuboids? Options:
A) 12 b ^ 2
B) 10 b ^ 2
C) 6 b ^ 2
D) 4 b ^ 2
E) 2 b ^ 2

Rationale: l = 2 b ; b = b ; h = b ; surface area = 2 * ( lb + bh + hl ) = 2 * ( 2 b ^ 2 + b ^ 2 + 2 b ^ 2 ) = 10 b ^ 2 answer : b
Answer: B