Two cubes, each of volume 125 cm3, are joined end to end. The surface area of the resulting solid is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 250 cm2
Two equal cubes joined face to face make a cuboid twice as long as one cube; the two faces that touch are hidden.
Side of each cube \(=\sqrt[3]{125}=5\) cm
Cuboid: \(l=10\) cm, \(b=5\) cm, \(h=5\) cm
Surface area \(=2(lb+bh+hl)=2(50+25+50)=\) 250 cm2
Shortcut:
Two cubes have \(2\times6=12\) faces of 25 cm2; joining hides 2 of them
\(10\times25=250\) cm2