The salary of a worker is first increased by 8% and then it is decreased by 8%. What is the percentage change in his salary?

Correct option is D

Given:
Salary is first increased by 8%
Then it is decreased by 8%
Formula Used:
When a value is increased by x% and then decreased by x%, the net percentage change is reduced by :
​$$\text{Net Change} = \frac{x^2}{100}$$ 

Solution:
Let x = 8
​$$\text{Net Change} = \frac{8^2}{100} = \frac{64}{100} = 0.64\%$$​​
So, the salary is reduced by 0.64%