The ratio of the length of diagonal of two cubes is 2 ∶ 3 and the difference between the total surface area of the bigger cube and the lateral surface area of the smaller cube is 342 cm2. Find the total surface area of a statue which is formed by placing the smaller cube upon the bigger cube.

The ratio of the length of diagonal of two cubes is 2 ∶ 3 and the difference between the total surface area of the bigger cube and the lateral surface area of the smaller cube is 342 cm2. Find the total surface area of a statue which is formed by placing the smaller cube upon the bigger cube. Correct Answer 630 cm<sup>2</sup>

Calculation:

Since, diagonal ratio = side ratio of cube = 2 ∶ 3

Let the ratio be x

So, the side of the first cube = 2x

And the side of the second cube = 3x

According to question,

The total surface area of the bigger cube – Lateral surface area of smaller cube = 342

So, 6 (3x)2 – 4 (2x)2 = 342

⇒ 38x2 = 342

So, x = 3

So, the side of the smaller cube = 2 × 3 = 6

And the side of the bigger cube = 3 × 3 = 9

So, the area of statue = total surface area of bigger cube + total surface area of the smaller cube – 2 × areas of one face of the smaller cube

So, the required area = 6 × 92 + 6 × 62 – 2 × 62

Hence, 630 cm2

Related Questions

What is the ratio of the volume of a cuboid to the volume of a cube? Statement I. The ratio of the height, breadth, and length of the cuboid is 1 : 2 : 3 and the total surface area of the cuboid is 352 cm2. Statement II. The total surface area of the cube is given to be 384 cm2. Statement III. The length of the cuboid is 3 times the height of the cuboid and 1.5 times the breadth of the cuboid. The difference between the length and the height of the cuboid is 8 cm.