Question

Three metallic solid cubes with edges of length 3cm, 4cm and 5cm respectively are melted and recast into a new solid cube. Find (1) volume and (2) surface area of new cube

Answer 1

Answer:

Step-by-step explanation:

Volume = 27 cm^3 +

64cm^3+125cm^3

= 216 cm^3

Length of one edge of new cube formed = 6 cm

Surface area = 6a^2

= 6×6×6

= 216 cm^2

Answer 2

Answer:

The volume of the new cube is 216cm³.

The Surface area of new cube is 216 cm².

Step-by-step explanation:

Given :

Volume of 1st cube - (3)² = 27 cm³.

Volume of 2nd cube - (4)³ = 64 cm³.

Volume of 3rd cube - (5)³ = 125 cm³.

To Find :

• Volume of the new cube.
• Surface area of the new cube.

Solution :

• Step 1 :
• Find the volume of the cube.

We know that :

Volume of the cube :

$\bigstar\;\boxed{\textsf{Volume of the cube}\bf=L \times L\times L = L^3}}$

But, We use this formula :

In the case of cube, L = B = H.

So,

Add the volume of the new Cubes,

⇒ 27 + 64 + 125.

⇒ 216 cm³

∴ Volume of the new Cube = 216 cm³

$\rule{300}{1.5}$

• Step 2 :
• Find the surface area.

Surface area = 6l² ; Hence, l = 6 cm.

⇒ 6(6)²

⇒ 6 × 36

⇒ 216 cm².

∴ The surface area of the new cube = 216 cm².