Question

A number is increased by 20% and then it is decreased by 20 % .find the net increase or decrease per cent

Answer 1

$4 \% \:\:decrease$

Step-by-step explanation:

$Let, \: \: number = 100 \\ A/Q, \: \: \: new \: \: number = 100 \times \: 120 \% \times 80 \% \\ = 100 \times \frac{120}{100} \times \frac{80}{100} \\ = 96 \\ decrease \: \: in \: \: given \: \: number \\ = 100 - 96 \\ = 4 \\Now, \: \: \boxed{decrease \: \: percent = \frac{decrease \: \: value}{number} \times 100} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{4}{100} \times 100 \\ = \boxed{4\% }$