Question

Ulute 100.
A solid cube is of side 20 cm. It is melted to form smaller cubes of side
5 cm. Find the number of smaller cubes formed.
5. Find the volume of a cube whose surface area is 1350 cm​

Answer 1

Answer:

20•20•20=x•5•5•5

x=64

1350=6a^2

a=15

a^3=3375

Answer 2

Answer:

No. of smaller cubes = 64

Volume of the other cube =  3375 $cm^{3}$

Step-by-step explanation:

Total volume of the solid cube= $20^{3}$ $cm^{3}$ = 8000 $cm^{3}$

Volume of a small cube = $5^{3 } cm^{3}$ = 125$cm^{3}$

∴ Number of smaller cubes formed = $\frac{8000}{125}$ = 64

Surface area = 1350 cm

Let the length of a side be $x$

              6 $x^{2}$ = 1350cm

                  $x$ = $\sqrt \frac{1350}{6}$ cm = $\sqrt{225}$ cm = 15 cm

∴ Volume = $15^{3} cm^{3}$ = 3375 $cm^{3}$