Three cubes each of side 5 cm are joined end to end. The surface area of the resulting cuboid is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 350 cm2.
We have three cubes, each side 5 cm, joined end to end to form a cuboid
So, length(l) = 3 × 5 = 15 cm
Breadth(b) = 5 cm
Height(h) = 5 cm
The surface area of a cuboid(SA) = 2(lb + bh + hl)
⇒ SA = 2(15 × 5 + 5 × 5 + 5 × 15)
⇒ SA = 2(75 + 25 + 75)
⇒ SA = 2 × 175 = 350 cm2