Question

A large cube is formed from the material obtained by melting three smaller cubes of 3,4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube?

A) 2 : 1 B) 3 : 2 C) 25 : 18 D) 27 : 20

Answer 1

Answer:

bro this is your ANSWER

Step-by-step explanation:

Let x be the edge of the large cube.

x

3

=3

3

+4

3

+5

3

⇒x

3

=27+64+125=216

⇒x=

3

216

=6cm

∴ Required ratio =

Surface area of larger cubes

Total surface area of smaller cubes

=

6(6)

2

6(3)

2

+6(4)

2

+6(5)

2

=

6×36

6×9+6×16+6×25

=

216

54+96+150

=

216

300

=

18

25

=25:18