Question

the difference between increasing a number by 5% and decreased by 5% is 20. what is number

Answer 1

Let the number be x
It is increased by 5% ⇒   $x + \frac{x}{20} = \frac{21x}{20}$
Also, it is decreased by 5% ⇒ $x - \frac{x}{20} = \frac{19x}{20}$

The difference between these two is 20

$\frac{21x}{20} - \frac{19x}{20} = 20$

⇒ 2x = 400

⇒ x = 200

The number is 200

Answer 2

let the no. be x
5%of x=5x/100
new no,after increament of 5%=x+5x/100=105x/100

new no,after decrement of 5%=x-5x/100=95x/100
According to question
105x/100  - 95x/100=20
10x/100=20
x=200