# An edge of a cube is increase by 10%.Find the percentage by which the surface area of the cube increases ? plz explain

2
by REVIL

Log in to add a comment

by REVIL

Log in to add a comment

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

Let the original edge of the cube be a

now the edge is increased by 10%

10% of a = 10/100 × a

= a/10

so the new cube edge = a/10 + a = 11a/10 =1.1 a

The surface area of the original cube = 6a²

and the surface area of new cube = 6 a² = 6× (1.1a)²

= 6 × 1.21 a²

= 7.26 a²

now the percentage increase in the surface area

new surface area - original surface area /original surface area × 100

= 7.26 a² - 6a² / 6a² × 100

= 1.26a²/6a² × 100

= 1.26 / 6 × 100

= 0.21 × 100

= 21 %

now the edge is increased by 10%

10% of a = 10/100 × a

= a/10

so the new cube edge = a/10 + a = 11a/10 =1.1 a

The surface area of the original cube = 6a²

and the surface area of new cube = 6 a² = 6× (1.1a)²

= 6 × 1.21 a²

= 7.26 a²

now the percentage increase in the surface area

new surface area - original surface area /original surface area × 100

= 7.26 a² - 6a² / 6a² × 100

= 1.26a²/6a² × 100

= 1.26 / 6 × 100

= 0.21 × 100

= 21 %

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

Let the original edge of the cube be "a"

now the edge is increased by 10%

10% of a = a/10

so the new cube edge = a/10 + a =1.1 a

The surface area of the original cube = 6a²

and the surface area of new cube = 6 a² = 6× (1.1a)²

= 7.26 a²

now the percentage increase in the surface area

new surface area - original surface area /original surface area × 100

= 7.26 a² - 6a² / 6a² × 100

= 1.26a²/6a² × 100

= 1.26 / 6 × 100

= 21 %

now the edge is increased by 10%

10% of a = a/10

so the new cube edge = a/10 + a =1.1 a

The surface area of the original cube = 6a²

and the surface area of new cube = 6 a² = 6× (1.1a)²

= 7.26 a²

now the percentage increase in the surface area

new surface area - original surface area /original surface area × 100

= 7.26 a² - 6a² / 6a² × 100

= 1.26a²/6a² × 100

= 1.26 / 6 × 100

= 21 %