Question

Each edge of a cube is increased by 50%, then what is the percentage increase in its surface area?

Answer 1

Let edge of cube =1
So surface area =6a²
=6x1²=6

After increasing 50%
Edge =1.5

Surface area =6x1.5²=13.5

Increase in surface area =13.5-6=7.5

In % =7.5/6 x100=125%

Hope it helps in case of any doubt comment below

Answer 2

Let edge of cube be a
So surface area will be 6 a ^2
Now,
Length increased = 50/100 * a
That is 1/2 *a
Now new edge will be = a + a/2
That is 3a/2
Surface area will be = 6 * (3a/2)^2
That is 6 * 9a^2/4
= 27 a^2/2
Now increase in surface area = new area - original area
= 27a^2/2- 6a^2
=15a^2/2

Now,
Profit %= profit /c. P *100
= 15a^2/2/6a^2* 100
= 15/12*100
=5/4*100
=5*25= 125%