Question

three equal cubes are place adjacent in a row. find the ratio of total surfaces area of the new cuboid to that of the sum of the surface area of the three cubes.

Answer 1

Let x be the length of the side of a cube.

Find the surface area of 3 cubes:

1 cube = 6 faces = 6x²

3 cubes = 18 faces = 18x²

Find the surface area of the cuboid:

number of faces = 14

Surface area = 14x²

Find the ratio of the cube to cuboid:

18x² : 14x²

Divide both sides by 2x² :

9 : 7

Answer: The ratio is 9 : 7

Answer 2

$\color{violet}{ \boxed{ \ \huge{ \underline{thanks \: for \: asking \: this \: question}}}}$

$\bold{ \huge{solution}}$

Let to be Surface Length of cube (X)
$\color{violet}{ \boxed{ \ \huge{ \underline{ \: then}}}}$


We know that Cubic have 3 faces..

then.
=) 9×2=18x²


Now,


Cuboid =7×2=14x²


Ratio of cube and Cuboid=

18x²=14x²

X² cancel


9=7


Answer:-

9:7


Thanks!!!