Sanjeeb's salary was first reduced by $50\%$ and then increased by $50\%$. What percentage of his salary does he lose?

Let Sanjeeb's initial salary be ₹$100$.Step 1: Salary is reduced by $50\%$ $
$\text{New Salary}=100-50\%\text{ of }100=₹50$$Step2:Salaryisincreasedby$ 50\%
$\text{Final Salary} = 50 + 50\% \text{ of } 50 = 50 + 25 = ₹75
Net loss in salary:
$$\text{Loss}=\text{Initial Salary}-\text{Final Salary}=100-75=₹25$$
$$\text{Loss Percentage}=\left(\frac{25}{100}\right)\times 100\%=25\%$$
Alternatively, using the successive percentage change formula $a+b+\frac{ab}{100}$:
$$-50+50+\frac{(-50)(50)}{100}=0-25=-25\%$$
The negative sign indicates a loss of $25\%$.