Robert's salary was decreased by 70% and subsequently increased by 70%. how much percentage does he lose? Choose the correct choice from the following answers.
A) 10 %
B) 20 %
C) 25 %
D) 30 %
E) 49 %

Rationale: "let original salary be $ 100 salary after decreasing 70 % = 100 - 100 x 70 / 100 = $ 30 salary after increasing 70 % on $ 30 = 30 + 30 x 70 / 100 = $ 51 percentage of loss = 100 - 51 = 49 % answer : e"
Answer: E