Robert's salary was decreased by 60% and subsequently increased by 60%. how much percentage does he lose?  Options:
A) 10 %  B) 20 %  C) 25 %  D) 36 %  E) 50 %

Rationale: let original salary be $ 100 salary after decreasing 60 % = 100 - 100 x 60 / 100 = $ 40 salary after increasing 60 % on $ 40 = 40 + 40 x 60 / 100 = $ 64 percentage of loss = 100 - 64 = 36 % answer : d
Answer: D