A's salary was decreased by 50% and subsequently increased by 50%. How much percent does he lose ?

Answer: Option A

Let A salary's in starting is = 100
Now after decreased by 50% A salary become = 50
Again 50% of salary increase i.e. 50% of 50 = 25
Current salary is = 50 + 25 = 75
Actual decrease in salary of A = 100 - 75 = 25
Actual % lose = $$\frac{25}{100}$$ × 100 = 25%