The length of each edge of the cube was increased by 40% 1. By what percentage did the volume of the cube increase?

The length of each edge of the cube was increased by 40% 1. By what percentage did the volume of the cube increase? 2. By what percentage has its surface area increased?

Let us denote the length of the edge of this cube by a. Let’s use the formulas and write down the volume and surface area of the cube:
V1 = a³;
S1 = 6 * a² = 6a².
After increasing by 40%, the length of the edge of the cube became equal to:
a + 40% = a * 1.4 = 1.4a.
Find the volume and surface area with the new data:
V2 = (1.4a) ³ = 2.744a³.
S2 = 6 * (1.4a) ² = 6 * 1.96a² = 11.76a².
We find the ratio of volumes and areas:
V2 / V1 = 2.744a³ / a³ = 2.744 or 274.4%.
274.4% – 100% = 174.4% – volume increase.
S2 / S1 = 11.76a² / 6a² = 1.96 or 196%.
196% – 100% = 96% – increase in surface area.
Answer: the volume has increased by 174.4%, the surface area of the cube has increased by 96%.