an edge of a cube is increased by 10 percent Find the percent by by which surface area of cube - Maths - Surface Areas and Volumes

Question

an edge of a cube is increased by 10 percent Find the percent by
by which surface area of cube is increased?

Shridhar Kaushik · Accepted Answer

Let the edge of the cube is x unit âˆ´ Surface area of the cube = 6x2 sq units Now the edge is increased by 10% âˆ´ Increase in edge $= \frac{10}{100} \times x = \frac{x}{10} Units$ So, the edge of new cube $x + \frac{x}{10} = \frac{11}{10} x Units$ âˆ´ Surface area of cube $= 6 \times (\frac{11}{10} x^{2}) = \frac{6 \times 121 x^{2}}{100} sq units$ Hence change in surface area of cube $= \frac{6 \times 121 x^{2}}{100} - 6 x^{2} = 6 x^{2} (\frac{121 - 100}{100}) = 6 x^{2} \times \frac{21}{100}$ âˆ´ The percent by which the surface area of cube is increased $= \frac{Change in S A}{Actual S A} \times 100 = \frac{6 x^{2} \times \frac{21}{100}}{6 x^{2}} \times 100 = \frac{21}{100} \times 100 = 21 %$

an edge of a cube is increased by 10 percent.Find the percent by by which surface area of cube is increased?