SSC CGL 2022 PYQ — Question 65

The correct answer is Option 4 i.e. 294 cm².

Given:

Length of diagonal of cube, d =  7 √3 cm

Concept Used:

Diagonal of cube = a√3    ....(i)

Surface area of cube = 6a²      ....(ii)

Explanation:

From equation (i), 7√3 = a√3

⇒ a = 7

Now, from equation (ii), we get

Surface area of cube = 6(7)²

⇒ Surface area of cube = 6 × 49

⇒ Surface area of cube = 294

Hence the surface area of the given cube is 294 cm².