Question

each edge of a cube us increased by 50% . The percentage increase in the surface are of the cube is ? Ans = 125% ... give me full solution

Answer 1

new edge= 150% of a
= 1.5 a

new surface area= 6 (1.5a)^2
= 6 2.25 a.a

increase = 6 a.a( 2.25-1)
= 6 a.a 1.25

percentage increase = 6a.a 1.25×100/ 6a.a
= 125

Answer 2

Let the edge of a cube be 'x'.

Given that  each edge of a cube increased by 50%.

⇒ x + 50% of x

⇒ x + x/2

⇒ 3x/2.

We know that surface area of a cube = 6x^2

⇒ 6(3x/2)^2

⇒ 54/4 x^2

⇒ 13.5 x^2.

So, the increase in area = 13.5x^2 - 6x^2

⇒ 7.5x^2.

Now,

% increase in area = (Increased area/original area) * 100

⇒ (7.5/6) * 100

⇒ 125%.

Hope this helps!